System Mode :2.4G wireless transmitter Communication distance :up to 50 meters Quantity of wireless channel :16 flash mode :TTL /M/MULTI Synchronous mode :front-curtain sync ,rear-curtain sync ,high -speed sync Packet control :A,B,C,D-4 groups sync speed :up to 1/8000s Focus lamp :with AF assist lamp input :hot shoe power :2AA batteries (not included ) or 2XAA Ni-mh batteries (not including ) .Standby Time :up to 60H
