Features: 16-selectable flash groups. Wireless triggering of flashes. 50 meters above the regulation distance, maximum sync speed of 1 /250sec. Switch the on-or-off of the modeling light or AF-assist beam, & buzzer. Supports two power display mode ( 5.0-10.0 or 1/1-1/128 ). Receiver Mini compact flash powered, no batteries. Large LCD display. Single point hot shoe, works with camera systems such as Canon, Nikon,Pentax, Olympus, etc. Compatible flash: Witkey series flash, QT series flash, QS series flash,Gemini GT series, Gemini GS series. Specifications: Model FT-16 Transmitter Power Supply 3V (2 * AA Ni-MH or alkaline batteries) (Not included) Receiver Power Supply 5V ( power by flashes) Transmit Frequency 433MHz wireless remote system Workable Distance 50m / 164ft (open areas) Control on Flashes Flash power ratio Modeling lamp or AF-assist beam on / off Buzzer on / off Power-ratio display mode Flash triggering Max. Sync. Speed 1 / 250 seconds Channel 16 Transmitter Size Approx. 13.5 * 5.1 * 3.5cm / 5.3 * 2.0 * 1.4in Transmitter Weight 63g / 2.2oz Receiver Size Approx. 5.6 * 3.0 * 1.7cm / 2.2 * 1.2 * 0.7in Receiver Weight 11g / 0.4oz Package Size 20.5 * 13.8 * 5cm / 8.1 * 5.4 * 1.9in Package Weight 140g / 5.0oz Package List: 1 * FT-16 Transmitter 1 * FT-16 Receiver 1 * User Manual (English & Chinese) Note: This item only includes the trigger set, the camera and speedlite not include.