Phottix® Tetra is used for triggering off-camera flashes and for studio flash made by  Canon/Nikon/Sigma/Olympus/Pentax/Vivitar.  Phottix® Tetra comprises a transmitter and a receiver. The transmitter mounts onto your camera's hot-shoe. The receiver is attached to any portable flashgun with a hot-shoe style base or PC sync cable.

The transmitter emits a wireless signal to the receiver when the shutter is triggered which, in turn, fires the flash. This allows you to take pictures with off-camera flash and not have to depend on your built-in flash as the trigger device. The unit works with all cameras that have a hot-shoe feature, but does not offer TTL or any form of automated camera control. You can also use older cameras or flashguns that don't have a hot-shoe facility.

The transmitter will take the 3.5mm PC cord to connect the PC socket of the camera. You can use the same 3.5mm PC (with 6mm converter) Sync cord to connect the receiver and studio light to trigger the studio light.

Features
1. Four channels to avoid interference
2. Receiver with PC Sync socket, good for studio flash
3. Channel selector outside receiver
4. Good for umbrella holder with L-bracket moving up to 90 degree (The L-bracket is aluminum, and can be mounted in a hot-shoe (it doesn't have any electrical contacts), or on a standard 1/4" screw mount. The locking knob allows the body of the receiver to be rotated relative to the L-bracket, and the indentations on the body allow it to be locked in the upright position, as well as 90 degrees forwards or backwards)
5. Use easily found AAA batteries for receiver
6. The receiver has an on/off switch, and an LED to indicate triggering
7. The transmitter is also a  compact unit
8. Works for majority of older flashes used with film cameras.

Specification
1.4 Channel with hot-shoe connector for external flashes
2.PC sync socket for studio flashes
3.Transmitter -- 12V compact accumulator 123A
4.Receiver – 2 x AAA batteries
5.Maximum working distance--30m/100ft (Open area without interference)