Qty: 1 - Color: Black - Material: Plastic + Aluminum alloy - Compatible camera: Canon / Nikon / Pentax - Shutter speed 1/250s - Transmitter battery: 1 x 12V 32A battery (included) - Receiver battery: 2 x AAA batteries (not included) - Max. distance: 20m - Frequency: 433MHz (max.) - This product is made of one transmitter and two receivers with FM radio wireless remote control - The transmitter can work more than 1 year trigger up to 30000 times trigger current is 0.31mA - The receiver speed up to 1/320s - This flash trigger unit has strong anti-interference function and has four channels for you to choose - It is extremely useful if there are several photographers working nearby - Each photographer could choose their own channel to trigger off the external flash unit they are going to use without triggering others because of overlapping signals - Packing list: - 1 x Transmitter - 2 x Receivers - 1 x PC cable (20cm)