Peak Design’s 45L travel pack is a clamshell that pretends to be smaller until you unzip the expansion. The useful public facts are the three volumes and the empty weight — about 4.5 lb / 2.05 kg on spec tables that match the brand’s geometry.
Four-sided access (top, front, side, rear) is the packing story: cubes go in like drawers. UltraZip weatherproof zippers and a recycled 400D canvas shell are manufacturer claims, not our abrasion test.
Why it is on the shortlist: published expand/compress range, a carry-on claim tied to the 35L “standard” state, and Peak Design’s lifetime guarantee language. Why it might not be yours: it is heavy for the liters, and the list price sits at the top of this hub.
We do not invent a comfort score for the hip belt. Try it loaded or read a tester who put a scale on it.