Wireless Flash Trigger\n\n- Control up to three groups of flash guns, each group comprising of one or more flash units\n- TTL & Manual mode\n- LCD indicates user-friendly status of each group\n- Hot shoe on transmitter allows speedlights in manual mode to be used with the Viper TTL\n- DCM (Digital Channel Matching) to provide reliable connections\n- Over 100m range\n- microUSB socket for firmware upgrade\n- Compatible with original speedlights\n- Easily adjust mode and values on a group by group basis