All hip packs are made with 1000 Denier Cordura nylon and 18oz Vinyl coated polyester. These things are perfect for the summertime when all you need is a few items. It sure beats riding with a full-sized bag on those hot days when all you need is something to carry your wallet/purse, keys, phone, cliff bar whatever. Both the large and small feature a mini u-lock holder.
This is the large, it measures 10" across 6.5" tall and 3" deep. There is also a 3d pocket on the front to keep some stuff separate.

Here's what the small hip packs look like. It measures 8" across 5.5" tall and 2.5" deep. Both the large and small version share the Ulock holder feature but the small doesn't have a front pocket. It's for people that have literally nothing to bring out besides a wallet, phone, and keys.