The Hahnel Viper TTL Wireless Flash Receiver from Hahnel works with the Viper Wireless Flash Trigger system for wirelessly triggering multiple flash units from a single camera. The system uses a 2.4 GHz frequency and has a 328′ range. Also, the receiver features a mini-USB port used to connect flash units as well as for firmware updates and external power. There is even a 2.5mm port for standard flash connections. Each receiver can run on two AA batteries.
