Based on traditional men's sizing, Truhks are super soft bamboo underwear that have a unique 3-layer pocket to securely hold your STP/soft packer in place.
Outbound Self-Packable Lightweight Nylon Backpack For Travel/Camping/Hiking, 12-L
Buy Calvin Klein Men's Micro Stretch Low Rise Trunk 5 Pack Underwear Black/Blue Shadow/Medium Grey/Cobalt Water (S, M, L, XL) - MyDeal
FTM Trans Dark Gray Brief STP/Packing Underwear
TrustyPup Travel Easy Explorer™ Travel Pet Carrier, Airline Approved, 18-in x 11-in x 10.5-in
Raleigh Rear Bike Basket
Packing-underwear – Other Nature GmbH
Packer Underwear
Men's Underwear, Bjorn Borg, Calvin Klein Underwear, BOSS
Best bike panniers: Waterproof backpacks to retro bike bags
Men's Underwear: Boxers, Briefs, Jockstrap