Boxes + Storage /

Monster Box 40 (Large) Storage Box for Sprinter

Boxes + Storage

Van Storage Box Monster 40 mounted on rear door of off-road van with fold-down work station and secure storage features.

Large black waterproof van storage box with fold-down door and steel mounting points for off-road gear storage

Large black van storage box with fold-down door and interior shelf, designed for secure and waterproof gear storage.

Open Box #4 Van Storage Box Monster 40 with fold-down door workstation, rugged waterproof construction, and ample space for off-road gear and essentials.

Van Storage Box Monster 40 mounted on open van door with snowboard gear outdoors

Large black Van Storage Box Monster 40 mounted on rear van door with two mountain bikes on top and rugged off-road design

Van Storage Box Monster 40 mounted on rear door of off-road van with spare tire and roof rack

Open black van storage box mounted on rear door with fold-down work station and waterproof design

Van storage box mounted on rear door of off-road van for secure gear storage and easy access

Man using large black van storage box mounted on rear door of off-road van with gear inside

Open box #4 Van storage box Monster 40 with fold-down door and waterproof TIG-welded steel construction for rugged off-road use

Black heavy-duty van storage box with tiger claw latches and perforated panels for mounting accessories

Open black van storage box with fold-down door and interior shelf for secure gear storage

Click Here to Contact Owl's Team

Monster Box 40 (Large) Storage Box for Sprinter

$1,750

Upgrade Options:

The best-selling rear door carrier on the market—entirely re-imagined. Capable of carrying an industry-leading 200 pounds of gear, the new B2 now comes with a complete Sherpa hole and slot panel, and even more modular capability.

B2: Sprinter Rear Door Cargo Carrier & Bike Rack • $1,900

This Product Fits:

Mercedes Sprinter, Winnebago Ekko, Winnebago Revel, Storyteller Overland, Tiffin GH1, Thor Sanctuary & Tranquility, Jayco Terrain, Airstream, Ford Transit, Ram Promaster

Lightweight aluminum, not heavy steel
8.8 cubic feet of storage, bigger than any others
Built in the USA, not imported
3 Year limited warranty from Owl
Adjustable shelf that can be moved up and down
Dual fold doors allow for maximum storage, bottom door acts as a table

Click Here to Contact Owl's Team

Why Choose Owl: Boxes

Choosing the right exterior storage box for your Mercedes-Benz Sprinter or adventure vehicle affects storage capacity, weight, durability, organization, and long-term usability on the road.

	Owl	Main Competitor
Material	Multi Gauge For Strength And Weight	Simgle Gauge (Increased Weight)
Country of Origin	USA	China / Overseas
Weight	45/65Lbs	55/75Lbs
Powder Coat	Dual Stage (Primer and Top Coat)	Single Stage
Welds	Robotic	Unknown
Accessory Panel	Yes	No, Or Additional Cost
Bi-Fold Doors	Yes	No
Rust Proof	Yes	No
Warranty	3yr - 36k OR 4yr - 40k if installed by Owl	Sold (as-is), No warranty
Servicing Support	6 Owl-Owned Retail & Service Locations	No Service Locations
Customer Service Reps On Call	Yes, at our HQ in Arizona	No
Original Inventor	Yes	No

Owl cargo boxes are designed for van life, overlanding, and expedition travel where lightweight construction, durability, weather resistance, and modular functionality matter. From bi-fold door access and integrated accessory panels to robotic welding and rust-proof aluminum construction, the system is engineered for real-world travel, daily usability, and long-term reliability both on and off the road.

Use Cases

Rear Storage for Van Life & Overland Travel
Add secure, external storage for tools, recovery gear, camping equipment, and daily essentials, keeping your Mercedes-Benz Sprinter interior clean and organized for van life and long-distance travel.

Camp Kitchen & Mobile Workstation Setup
Integrated fold-down door and internal shelf create a convenient table and prep surface for cooking, gear organization, and campsite setup during overlanding and camping trips.

Gear Organization for Expedition & Off-Grid Builds
Perfect for storing recovery gear, spare parts, tools, and accessories needed for remote travel, trail repairs, and self-sufficient overland adventures.

Modular Storage & Accessory Mounting Platform
Designed to integrate with bike racks, gear mounts, and Owl accessory systems, allowing flexible setups for bikes, storage, and expedition equipment.

Daily Use, Travel & Easy Gear Access
Quick-access design makes it easy to grab gear, organize equipment, and use the box as a workspace whether you’re on the road, at camp, or prepping for your next adventure.

Boxes - Manufactured in the USA

The OWL Monster series of boxes is designed and manufactured in the USA. We take enormous pride in supporting domestically made products, which allows us to control the build and finish quality of each piece. We are obsessive, so you are always ready.

Black Monster 30 van storage box mounted on a vehicle at sunset for outdoor adventure use

Massive Size, Minimal Weight

The Owl Monster 30 is the perfect secondary storage space for any gear that's better left outside the van. With 6.65 cubic feet of internal storage, it's ideal for recovery gear, tools, dirty shoes, and even misbehaving children. (Please do not put children inside the box.) All of this storage space comes in at less than 60 pounds because of our lightweight, TIG-welded aluminum.

Key Features

Dual-Fold Door

Built to maximize storage - the bottom door folds down, creating a stable work surface for setting up a grill, food prep, or other outdoor tasks. Bottom door has built in slam latch for simple fast closing, top door has gas struts to stay open.

Modular Gear Plates

The front of the Monster XL box features Owl’s signature hole and slot design, making it easy to mount must-have trail accessories. (Shovel shown is not included.)

Versatile Mounting

While the Monster XL box can mount to almost anything, it is pre-drilled for the Owl B2/B2 Pro. Locking latches keep all your gear safe, and prevent box removal.

Adjustable Shelf

The Monster XL box comes standard with one adjustable shelf, which can be moved up or down as needed. Additional shelves can be purchased separately.

What Our Customers Say

Trust our Verified Reviews from Google. Read More.

Vehicle Compatibility

Compatible with These Vehicles

View Compatibility +

This product is designed for 2019–present Mercedes-Benz Sprinter vans (VS30 platform), including the following configurations:
Sprinter 144" wheelbase
Sprinter 170" wheelbase
Sprinter 2500
Sprinter 3500 / 3500XD (where applicable)
Sprinter AWD (2023–present)
Sprinter 4x4 (2019–2022)

This product is compatible with most camper vans and adventure vans built on the 2019+ Sprinter platform, including popular models from Winnebago, Storyteller Overland, Thor Motor Coach, Airstream, and others.

Winnebago EKKO (Sprinter Platform):
- EKKO Sprinter 23B (2023–present)
- Mercedes-Benz Sprinter 3500 AWD (VS30) chassis

Compatible RV & upfitter platforms built on the Sprinter chassis include:

Winnebago Revel:
44C, 44E, 44N

Storyteller Overland:
Classic MODE, Stealth MODE, Beast MODE
144" High Roof AWD Sprinter builds
170" High Roof AWD Sprinter builds

Thor Motor Coach:
Tranquility: 19A, 19M, 19P, 24A, 24C
Sanctuary: 19A, 19L, 19M, 19P

Airstream:
Interstate 19GT / 19GTX / 19X
Interstate 24GT / 24GL / 24X

3500/4500 Cab Chassis:
Wayfair
Winnebago Navion
Winnebago View

3500 Dually Class B Vans:
Tiffin GT2
Winnebago Boldt

Other Platforms:
Tiffin GH1 (2025–present)
Jayco Terrain (2022–present)
Entegra Launch

Not With These Vehicles

View Compatibility +

Ford Transit-based vans
Ram ProMaster-based vans
INEOS Grenadier
INEOS Quartermaster

RETURNS

We want you to be delighted with your Owl gear! We accept returns up to 30 days from the date of shipment. For more information, visit

Owl Warranty, Cancellations & Returns

CALIFORNA PROP 65

Some parts offered by Owl contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit

Monster Box 40 (Large) Storage Box for Sprinter

Why Choose Owl: Boxes

Monster Box Overview

Use Cases

Boxes - Manufactured in the USA

Massive Size, Minimal Weight

Key Features

What Our Customers Say

Vehicle Compatibility

Compatible with These Vehicles

Not With These Vehicles

RETURNS

CALIFORNA PROP 65