Features: This set consists of a signal sender and two receiver trigger. Universal hot shoe interface, compatible with Canon, Nikon, Sigma, Olympus, Pentax, etc. (except Minolta SONY, for they use a special hot shoe). Globally univeral 433Mhz frequency, 4 channels. With studio flash interface, can trigger several kinds of studio flashes. Transmitting distance up to 30M, no limits with directions or angles. 1/4" nut can be connected with tripod or light holder to make flashlight safe and stable. Energy-saving design with 12V 23A battery of transmitter and 2 * AAA batteries(not included) of receiver. Comes with a PC sync cord for cameras without hot shoe socket. Note: This trigger do not support TTL function. Specifications: Power of transmitter: 23A 12V mini battery(included) Power of the receiver(AC): 2 * 1.5V AAA Alkaline Battery(not included) Outdoor working distance: max. 30m / 90feet (open area, no fraise) Indoor operating distance: max. 25m / 75feet Channel: 4 channels Frequency: 433Mhz Synchronous speed: Max. 1/250sec Color: black Material: metal + plastic Package size: approx. 10 * 8.5 * 5cm / 3.9 * 3.4 * 2.0in Package weight: 113g / 4.0oz Package Lists: 1 * 4-channel Transmitter 2 * 4-channel Receivers 1 * PC Sync Cord(2.5mm to PC) 1 * User Manual(English) Note: This item only includes the trigger set and sync cord.