TTL Compatibility - Nikon i-TTL Frequency: 433MHz Channels: 52 Channels over 26 Frequencies Antenna: Internal Transmit output power: Less than 0.001 watt (1/1000 of a watt or 1 milliwatt) Maximum Range (In optimum conditions): 800 feet (240 Meters) for i-TTL triggering 1200 feet (365 Meters) for standard triggering Mounting: Hot-shoe only Maximum Shooting Rate: Frames per Second (fps) 8 fps for E-TTL II & normal triggering Power / Channel Switch: OFF - C.2 - C.1 Status Indicator: LED, Green, Amber, Red status indications Voltage Present: 3.3 VDC (all pins) - safe for all cameras Hot Shoe voltage protection Hot Shoe: up to 50V USB: USB Compliant 2.0, Mini-B Connector Operating Temperature: above -15C (5 F) and below 50 C (120 F) Storage Temperature:(without battery) above -30 C (-22 F) and below 85 C (185 F) Construction: High impact plastic, captive battery door Hot shoe made of glass reinforced resin Power: 3 V Lithium battery, CR2450 (included) or CR2354 Lithium coin cell type Battery Life: Hundreds of hours of camera "awake time" depending on shooting habits Dimensions: 7.1 cm long x 4.9 cm wide x 3.3 cm tall Weight: 65 grams, 57 grams without battery