This is a wireless remote control from OM SYSTEM (requires 1 CR2032 battery). It can also be used wired with the included cable (no battery required). - Model Name: RM-WR1 - Brand: OM SYSTEM - Connectivity: Wireless, Cable - Included: Cable, Instruction Manual, Warranty - Function: Remote Shutter - Wireless Compatible Models: OM-1, OM-1mk2, OM-5 Thank you for looking. I am selling this as I have sold my OM-1. If anyone is interested, I'd be happy to pass it on. While it requires a battery, it's very convenient without the cable. If the battery dies, you can still use the cable. I will also include the used battery. I will ship via Yu-Packet Plus.