[2.4GHZ Wireless Flash Trigger]-The WF1 2.4G flash trigger transmitter and receiver provides stable wireless transmission,Transmission distance reaches up to 49.2 ft/15m ,ensuring reliable flash triggering.Both of transmitter and the receiver that can be used as a flash heightener for cameras with long lens.(Noted:The transmitter has a constant yellow light on. The receiver has a constant green light on. ) [Single-contact Hot Shoe mount]-The WF1 flash trigger with single-contact hot shoe is easy to install and use, compatible for most of cameras and camera flashes with single-contact hot shoe mount . [Built-in Rechargeable Battery]-MEDALight WF1 wireless trigger transmitter and receiver with 180Mah built-in battery, with our WF1 flash trigger that you just need to find a power source to recharge it.It comes with a 2 in 1 Type-c charge cable.(Noted:The blue light flashes is in charging state,blue light constantly on is fully charged) [Easy Setup]-The WF1 flash trigger is simple operation and quick setup, saving time and effort for photographers. [Widely Compatible]-The WF1 flash trigger transmitter and receiver compatible for most of the cameras&camera flashes with single-contact hot shoe mount for Cannon,Nikon,Sony,Fuji,Pentax,Olympus,etc,. Specification Model: WF1 Communication Frequency: 2.4GHZ Transmitter and Receiver Power by:Built-in 180Mah rechargeble battery(Include 2 in 1 Type-C charging cable) Outdoor operation distance: max. 15m / 49feet (open area, no fraise) Indoor operation distance: max. 15m /49feet Synchronous speed:approximately 30ns Transmitter Dimension: max. 15m /49feet Receiver Dimension: max. 15m /49feet Color: Black Material: Metal + Plastic How to use the WF1 2.4GHZ wireless flash trigger？ 1.Insert the transmitter's hot shoe socket into your camera's hot shoe mount, and insert the flash onto the receiver’s hot shoe mount. 2.Press the power button for 5 seconds to turn on the transmitter and the receiver.（Noted:If the flash trigger is paired,the transmitter has a constantly yellow light on, and the receiver has a constantly green light on.) 3.Then start your photo shooting with our WF1 flash trigger transmitter and receiver. 4.If the battery power is lower than 3.3V, the red light flashes at a frequency of 350ms. 5.When USB is plugged in and in charging state (battery voltage < 4.2V), the blue light flashes. 6.After fully charged (battery voltage ≥ 4.2V), the blue light is constantly on,when USB is unplugged, all lights are off. 7.The maximum communication distance is 15m. 8.If there is no any operation for more than 1 hour, the device will automatically turn off. How to resetting the WF1 Flash Trigger? 1.Press the pairing button(signal button) and power button simultaneously for 5 seconds to restore factory settings. The yellow light flashes three times and then the red light is constantly on. After restoration, there is no distinction between transmitter and receiver. 2.After restoration,press the pairing button briefly for 1 second(the signal button). The green light flashes to configure as a receiver. At this time, the green light is constantly on. 3.After restoration,press the pairing button for 5 seconds. The red and green lights flash alternately to configure as a transmitter. At this time, the yellow light is constantly on. 4.Press the power button for 5 seconds to turn off.and press the power button for 5 seconds to turn on. If the device has been paired, it will light up yellow (transmitter) or green light(receiver) after startup. If the flash trigger is not paired, the red light is constantly on.