45L / 55L / 65L IPX8 Waterproof Caving Backpack with Natural Rubber Seal

Sealock manufactures the SL-J033 Waterproof Caving Backpack for expedition use — caving, canyoning, river tracing and swimming through passages where a wet pack ends the trip. As a welded waterproof-bag factory, we build the body from TPU polyurethane laminated onto 420D nylon, join every seam with seamless high-frequency welding, and seal the opening with a natural rubber closure strip that compresses shut under the roll-and-clip flap. That construction gives this waterproof caving backpack an IPX8 rating — full submersion protection, not rain resistance — and Sealock is a designated partner supplier to Exploration China, the country's expedition community.

At a Glance

• IPX8 with a natural rubber seal — rubber closure strip on a seamlessly welded body.
• Three sizes — 45L, 55L and 65L on the same 34 × 23 cm footprint.
• Heavy-duty abrasion base — reinforced bottom for dragging through cave passages.
• Full load harness — padded straps, sternum strap, hip belt and haul handle.
• Trusted in the field — a designated partner supplier to Exploration China.

Natural Rubber Seal, IPX8

The opening closes on a natural rubber sealing strip: fold the flap over, run the central compression strap down and clip it, and the rubber compresses into a continuous seal along the mouth of the bag. Combined with the seamlessly welded TPU body — no stitch holes anywhere in the shell — it holds an IPX8 rating, so the pack keeps kit dry through full submersion in a sump, a swim-through or a canyon pool. We verify the seal on every unit with a full water-immersion test, submerging the closed pack for more than two hours and confirming the inside stays dry.

Built to Be Dragged

Caving destroys ordinary packs. This one has a heavy-duty reinforced base in contrasting black — the panel that takes the punishment when you haul the bag across rock, drop it down a pitch or drag it through a crawl. The TPU-on-420D-nylon shell resists abrasion and tearing, side lash cords let you cinch or clip gear, and a reinforced haul handle at the top gives you something solid to pull on. Reflective piping along the flap keeps the pack visible under headlamp light.

Three Sizes for Different Trips

Size	Dimensions (W × D × H)	Net Weight
45L	34 × 23 × 58 cm	1,916 g
55L	34 × 23 × 68 cm	1,968 g
65L	34 × 23 × 78 cm	2,043 g

All three share the same 34 × 23 cm footprint, so a bigger pack does not get wider in a tight passage — only taller. Hand measurement may vary by 3–5 cm, which is within normal tolerance.

Full Load-Carrying Harness

Because these are expedition loads, the harness is a complete one: padded contoured shoulder straps, an adjustable sternum strap, a padded hip belt that transfers weight onto the hips, and a padded back panel that cushions hard gear against your spine. A moulded haul handle sits at the top for lifting and hauling the pack between team members.

Storage and Organization

Inside, an internal mesh pocket keeps small items — a spare light, batteries, a first-aid kit — off the bottom of the main compartment and findable in the dark. Outside, a side pocket takes a bottle or a topo, and a hook-and-loop patch panel on the front carries team, club or expedition patches.

1. Engineering Specifications

Item	Specification
Brand	SEALOCK
Model No.	SL-J033
Product Name	Waterproof Caving Backpack
Product Category	Waterproof Backpack / Expedition Dry Pack
Construction Type	Top-Loading Cylindrical Expedition Pack
Manufacturing Process	Seamless High-Frequency Welding
Waterproof Structure	Seamlessly Welded TPU Body + Natural Rubber Sealing Strip
Closure Type	Natural Rubber Seal + Fold-Over Flap + Central Compression Strap
Waterproof Rating	IPX8
Available Sizes	45L / 55L / 65L
Dimensions — 45L	34 × 23 × 58 cm
Dimensions — 55L	34 × 23 × 68 cm
Dimensions — 65L	34 × 23 × 78 cm
Net Weight	1,916 g / 1,968 g / 2,043 g
Dimensional Tolerance	±3–5 cm (hand measurement)
Base	Heavy-Duty Reinforced Abrasion Base
Interior	Internal Mesh Pocket
Exterior	Side Pocket · Side Lash Cords · Hook-and-Loop Patch Panel · Reflective Piping
Carry System	Padded Shoulder Straps + Sternum Strap + Padded Hip Belt + Haul Handle
Colour	Yellow / Black
Country of Origin	Guangdong, China

2. Material Specifications

Component	Material	Purpose
Outer Shell	TPU Polyurethane Laminated on 420D Nylon	Waterproofing with abrasion and tear resistance
Seams	Seamless High-Frequency Welded	Needle-hole-free joints for IPX8 sealing
Closure Seal	Natural Rubber Sealing Strip	Compresses into a continuous seal at the opening
Base Panel	Reinforced Heavy-Duty Laminate	Survives dragging and hauling over rock
Compression Strap	Nylon Webbing with Buckle	Clamps the flap down onto the rubber seal
Lash Cords	Elastic Cord with Cord Locks	External gear attachment and load cinching
Reflective Trim	Reflective Piping	Visibility under headlamp and low light
Back Panel	Foam Padding with Fabric Cover	Cushions hard gear against the back
Shoulder Straps	Contoured Foam-Padded Webbing	Load distribution on expedition weights
Hip Belt	Padded Webbing with Quick-Release Buckle	Transfers load onto the hips
Haul Handle	Moulded Reinforced Handle	Lifting, hauling and passing between team members
Patch Panel	Hook-and-Loop Field	Team, club or expedition patches
Internal Pocket	Mesh	Keeps small items findable in the dark

3. Functional Specifications

Feature	Description
Submersible Protection (IPX8)	Rubber seal on a seamlessly welded body keeps kit dry through full submersion in sumps and pools.
Natural Rubber Sealing	Compressible rubber strip forms a continuous seal that stays reliable through repeated cycles.
Drag & Haul Durability	Reinforced base and TPU-on-nylon shell survive being dragged, dropped and hauled over rock.
Expedition Load Carry	Padded harness with hip belt transfers 45–65L loads onto the hips over long approaches.
Low-Light Visibility	Reflective piping picks up headlamp light in caves and at night.
Consistent Footprint	All three sizes share 34 × 23 cm, so larger volumes do not get wider in tight passages.
Internal Organization	Mesh pocket keeps lights, batteries and first aid off the bottom of the pack.
External Attachment	Side lash cords and patch panel for gear and team identification.
Easy Maintenance	Welded TPU surface rinses clean of cave mud and silt.

4. Customization / OEM Specifications

Option	Available
Sizes	45L / 55L / 65L · other capacities on request
Fabric Colour	Yellow/black stock · custom Pantone / two-tone
Fabric Type	TPU on 420D nylon (standard) · alternative denier / PVC to spec
Closure Type	Natural rubber seal (standard) · roll-top · airtight zipper
Base Reinforcement	Standard or upgraded thickness
Harness	Configurable straps, sternum strap and hip belt sizing
Internal Divider / Pockets	Optional
Haul Loops / Anchor Points	Optional additional loops for pitch hauling
Drain Grommet	Optional
MOLLE / Lash Webbing	Optional
Reflective Trim	Standard · extendable
Logo Methods	Welded patch · Silk-screen · Heat-transfer · Rubber patch · Embroidery
Full Custom Development	Ground-up development from sketch, sample or target spec
MOQ	300 pcs*
Sample Lead Time	7–15 days*
Production Lead Time	30–45 days*
Factory Audit	Available
OEM / ODM	Supported

Our OEM/ODM capability goes well beyond colour and logo changes: bring a sketch, a sample or a target spec — capacity, IPX rating, closure type, fabric, harness and haul-point layout — and our China base develops it from the ground up into a finished original product. Expedition packs in particular are often built to a club's or brand's own rigging requirements; share your spec and launch date and we will schedule sampling.

5. Packaging Specifications

Item	Details
Individual Packaging	PE / PP Bag
Carton Type	5-Layer Export Carton
OEM Carton Printing	Available
Barcode Label	Available
Hang Tag / Care Label	Available (OEM)
Shipping Mark	Available
Pallet Packing	Optional

Recommended Use

Activity	Suitability
Caving / Speleology	✔
Canyoning / River Tracing	✔
Rock Climbing	✔
Swimming Through / Sump Crossing	✔
Snorkeling	✔
Camping / Expeditions	✔
Rafting / Kayaking	✔

Quality Inspection Standards

Inspection Item	Standard
Fabric Inspection	100%
Weld Seam Inspection	100%
Rubber Seal Fit & Compression Check	100%
Full Water-Immersion Test (2+ hours)	Batch sampling
Base Abrasion Check	Batch sampling
Harness, Hip Belt & Haul Handle Load Test	Random sampling
Colour Consistency	100% vs. signed sample
Appearance Inspection	100%
Carton Inspection	100%

Inspection runs IQC on incoming TPU-nylon laminate, rubber sealing strip and hardware, IPQC on welds and seal installation in process, and OQC before shipment with an AQL check, a batch immersion test and a signed golden-sample comparison. Third-party inspection (SGS / QIMA) is available on request.

Product Highlights

Feature	Advantage
Natural Rubber Seal	Continuous compressible seal that survives repeated wet cycles
Seamless Welded TPU on 420D Nylon	No needle holes, with the tear strength of a nylon base cloth
IPX8 Rating	Full submersion protection for sumps, pools and swim-throughs
Reinforced Abrasion Base	Takes the damage of dragging and hauling over rock
Three Sizes, One Footprint	More volume without getting wider in tight passages
Exploration China Partner Supplier	Field-proven with an established expedition community

Printing & Logo Options

Brand it your way: welded patch, silk-screen, heat-transfer, moulded rubber patch and embroidery — plus the hook-and-loop panel for interchangeable team and expedition patches.

OEM / ODM and Wholesale

As the factory, we supply the SL-J033 for OEM, ODM and wholesale buyers from an MOQ of 300 pcs,* FOB Guangdong, with samples in 7–15 days and production in 30–45 days. We customize sizes, colours, fabric, closure type, base reinforcement, harness sizing, haul points and your logo, and we offer full ground-up custom development. For a custom or wholesale expedition dry pack program under your own brand or club, send your spec and target quantity and we will quote against it.

Need a technical trekking pack instead? See our technical waterproof hiking backpack. Want a large roll-top dry backpack? See our 45L roll-top dry backpack.

FAQ

How does the natural rubber seal work?

The opening carries a natural rubber sealing strip. You fold the flap over and clip the central compression strap, which compresses the rubber into a continuous seal along the mouth of the bag — the closure that gives the pack its IPX8 rating.

Is it really submersible?

Yes. The seamlessly welded TPU-on-420D-nylon body has no stitch holes, and with the rubber seal closed the pack is rated IPX8. Every unit is verified with a full water-immersion test of more than two hours.

Which size should I choose?

All three share a 34 × 23 cm footprint and differ only in height: 45L (58 cm) for day trips, 55L (68 cm) for longer routes, 65L (78 cm) for expedition loads. Hand measurement may vary by 3–5 cm.

What are the MOQ and lead times?

MOQ is 300 pcs,* FOB Guangdong, with samples in 7–15 days and production in 30–45 days. Custom sizes, colours, closures and logos are available. Send your spec for a quote.

Request a Quote

Sealock (YiFuLong Outdoor Gear Co., Ltd.) has built welded waterproof gear in Guangdong since 2003 and is a designated partner supplier to Exploration China. To order the SL-J033 in 45L, 55L or 65L, or to start an OEM/ODM program, send us your sizes, colours, logo and target quantity for pricing and lead time. MOQ 300 pcs · samples 7–15 days · production 30–45 days.

YiFuLong Outdoor Gear Co., Ltd. (Sealock)
Email: info@sealock.com.hk · Tel: +86-13632981825