From Think Tank Photo:
Sometimes all you need is just enough storage to hold one back-up battery and a CF or SD card. In April, we will release the CF/SD + Battery Wallet, a lightweight, secure, and convenient wallet for carrying a spare memory card and battery. No more fumbling for essentials, it’s all here in this compact package. Its organization makes this a must-have for anyone seeking small accessory management.
KEY STORAGE
MATERIALS
Exterior: For superior water resistance, all exterior fabric has a durable water-repellant coating, plus the underside of the fabric has a polyurethane coating. It also has 420D diamond rip–stop nylon, 420D high–density nylon, nylon binding, and 3–ply bonded nylon thread.