The RadioPopper Nano Transmitter is part of a wireless radio triggering system that can fire your flash at distances up to 1,750' depending on the prevailing conditions. The 4-channel Nano Transmitter features simple push-button operation and is compatible with any camera body with a standard hot shoe. DSLRs can sync up to 1/250 sec. and leaf shutter cameras up to 1/500 sec. The Nano gets approximately 150-300 hours of running time from the single, included CR123A battery. An LED gauge indicates remaining power. The Nano Transmitter requires separate purchase of a Nano, PX or JrX receiver for use.