The 5.11 Tactical Battery Case fits 4 AA or 4 CR123 or any combination. You should never be without your power source and with the waterproof case, you won't have to be. The 5.11 Battery Case is made of polymer PC/ABS material with an aluminum thumb dial that can be operated with gloves on. You'll never have to fret about batteries again with the 5.11 Battery Holder.