Feature: Universal hot shoe interface, compatible with for Canon, for Nikon, for Sigma, for Olympus, for Pentax, etc.  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.  Speedy frequency regulation, convinient for photographers to shoot.  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.  Specifications: Power of transmitter: 23A 12V mini battery(included, about one year lifetime);  Power of the receiver(AC): 2 X1.5V AAA Alkaline Battery(not included);  Outdoor working distance: max. 15m / 49 feet (open area, no fraise);  Indoor operating distance: max. 10m / 32 feet;  Channel: 4 channels;  Frequency: 433Mhz;  Synchronous speed: Max. 1/250sec;  Umbrella socket: approx. 0.8cm / 0.24in;  Material: metal + plastic;  Package size: approx. 7.5X6.5 X4.6cm;  Package weight: 86g / 2.99oz;  How to use: Insert the transmitters hot shoe socket into your cameras hot shoe jack, plug the flash onto the receiver, switch ON the receiver. Make sure the channel selector of both transmitter and receiver at same channel. Press the Test button on the transmitter to test before shooting.  If your camera has not hot shoe socket for connecting the transmitter you can connect the transmitter to the camera by the PC Sync Cord provided. (only the old camera needed).  You can trigger both the flashgun and studio lights with this flash trigger. If you use the receiver on big studio strobe flashlight or AC slave flash, you can just connect the receiver to the studio strobe flashlight with 3.5mm or 6.35mm jack plug PC Sync cord(not included).  This wireless flash trigger is made up of two parts: Signal Transmitter and Receiver. The signal transmitter adopts the advanced circuit and components. It can transmit wireless signal that is being encoded with low power consumption. The receiver works with two AAA-type batteries and decodes with microprocessor, it can trigger up to two flash units simultaneously, so you can increase the flash power with an extra flash unit.  Package included: 1 x Transmitter(23A 12V battery included);  2 x Receiver(AAA batteries NOT included);  1 x PC Sync Cord(2.5mm to PC);  1 x User Manual;