Peak Design Travel Backpack 45L: one bag for a week, and the weight it costs

Size changes with the trip. 30 L compressed for a day, 35 L for carry-on, 45 L when you can check it or need more room [2]. Owners who've traveled with it call it roomy with packing cubes [3].

Access from every side. Top, side, front and rear openings [1] mean you don't have to unpack everything to reach a jacket.

Looks like luggage when it needs to. The harness and hip belt tuck away [2], so it slides into an overhead bin or under a seat cleanly.

Tough shell. A 400D recycled shell with a 900D bottom [2] stands up to airport floors and truck beds.

Lasts. A four-year owner still takes it on trips [4].

Warranty. Peak Design's lifetime warranty covers defects and functional failures [9].

Heavy. At 2.05 kg empty [2], it eats into airline weight limits. An owner says it's heavy for clothes-only trips [3].

Straps when overpacked. A four-year owner says the straps get uncomfortable when it's overpacked [4]. A three-month owner feels the straps flex when the pack is heavy [5].

Cubes cost extra. Peak Design designed it around its own cubes and pouches, sold separately [2][8].

Expanded size. At 45 L, it's no longer a strict carry-on on many airlines [2]. Use the 35 L shape when flying.

• One-bag travelers on trips of a week or more [2][3].
• Photographers who want to carry Camera Cubes in a travel bag [2].
• Road-trippers who want a bag that opens like a suitcase [1][2].

• Light packers. Owners say it's heavy for clothes-only trips [3]. Peak Design also makes a 30L Travel Backpack [2].
• Everyday commuters. The Everyday Backpack 20L suits daily carry [6].
• Anyone hiking with it. It's a travel bag, and owners say the straps flex under heavy loads [5].
• People who need a hard case for fragile gear. See the Pelican 1510.

Road trips. Clamshell-style access [1] makes it a good duffel replacement in a truck or van. Pull out a layer without unloading the whole bag.

Dust. The UltraZips are weatherproof [1], not dustproof. Keep it zipped and off the ground at camp, and brush grit from the zips.

Cold nights. A puffer and a warm layer fit in the expanded 45 L shape [2]. Desert nights can be much colder than the days.

Water bottles. Use the expandable side pockets [2] for bottles, but don't plan to hike with it; owners say the straps flex when it's heavy [5].

Heat. Don't leave electronics packed inside in a hot car.

• Owners who've traveled with the 45L call it roomy with packing cubes. One says it's heavy for clothes-only trips [3].
• A four-year owner still takes it on trips and says the straps get uncomfortable if it's overpacked [4].
• After three months, an owner likes how the bag works and feels the straps flex when the pack is heavy [5].