Underseater – Cabin Backpack 40x30x20 with TSA Lock – Black

Lundholm Underseater Waterproof Backpack - 15.6 inch Laptop Bag with TSA Lock

Meet the Underseater waterproof backpack from the exclusive collection by Scandinavian brand Lundholm. This sleek, versatile backpack in elegant black pairs Scandinavian design with unmatched functionality. Perfect for the modern traveler or professional on the move – whether for work, study or a flight. Thanks to the waterproof zippers and high-quality materials, your things stay dry and safe, even in an unexpected downpour. With the built-in TSA lock and the smart suitcase-style layout inside, this is the ideal underseater for carry-on travel.

Benefits

This premium backpack was designed with an eye for detail and everyday ease. Made from durable, fully waterproof material, it gives your gear the best possible protection against moisture. The clever suitcase-inspired layout, with a padded 15.6 inch laptop compartment at the back, roomy sections and handy slip pockets, keeps everything organized and easy to find. The compression straps on both sides let you cinch the bag down for a compact fit. With a safety zipper for extra security, a dedicated pocket for your water bottle and several zip pockets, this backpack earns its place in daily use and on the road. And thanks to its carry-on friendly dimensions, it comes along on the plane without a fuss.

Specifications

• Made from high-quality, fully waterproof material
• Waterproof zippers for the best protection
• Padded laptop compartment that fits 15.6 inch laptops (positioned at the back)
• Smart suitcase-style layout with roomy sections and slip pockets
• Back pocket with zipper and TSA lock for secure storage
• Compression straps on both sides to adjust the size
• Dedicated pocket for a water bottle
• Several zip pockets for organized storage
• Carry-on friendly (fits under the seat) Dimensions: 40 cm x 30 cm x 16 cm
• 22L - Maximum use of space
• Color: Black
• Scandinavian Design

Which airlines let the Underseater fly free?

At 40 x 30 x 16 cm, the Underseater stays within the free under-seat size (40 x 30 x 20 cm) of almost every airline – so you pay nothing extra for hand luggage:

• Ryanair – free 40 x 30 x 20 cm (increased in 2026): fits
• Transavia – free 40 x 30 x 20 cm, max 10 kg: fits
• Wizz Air – free 40 x 30 x 20 cm: fits
• easyJet – free 45 x 36 x 20 cm: fits with room to spare
• Eurowings – free 40 x 30 x 25 cm: fits
• TUI fly, Corendon and Vueling – free 40 x 30 x 20 cm: fits
• KLM and Lufthansa – fits as included hand luggage or carry-on

Check the current rules per airline in our hand luggage guide and the 2026 comparison table. Airlines can change their rules – always check your own booking.

Frequently asked questions

Does the Underseater fit as free hand luggage on the plane?
Yes. At 40 x 30 x 16 cm it stays within the common free under-seat size of 40 x 30 x 20 cm at Ryanair, Wizz Air, Transavia, easyJet, Eurowings, TUI fly, Corendon and Vueling, among others.

Which laptop fits inside?
There is a padded compartment at the back for a laptop up to 15.6 inch, easy to take out separately at security.

Is the backpack waterproof?
Yes, it is made from fully waterproof material with waterproof zippers, so your laptop and clothes stay dry.

What is a TSA lock?
A lock that customs can open with a universal key without forcing it – your things stay safe, even if the bag has to travel as checked luggage for once.

How much fits inside?
22 liters, with a suitcase-style layout, laptop compartment, bottle pocket, several zip pockets and compression straps to pull the bag compact.

Lundholm - Quality Design | Scandinavian Elegance

Lundholm stands for high quality and timeless design. Built on the Scandinavian values of durability, simplicity and function, Lundholm creates products that are beautiful to look at and made to last. The Underseater collection carries that vision with a modern, practical touch – perfect for anyone who wants style, security and easy travel in one bag.