The size of the OVX306 tx module is the same size as for whoop_vtx and for whoop_vtx_hp, and the interface are also exactly the same, which can completely replace for whoop_vtx and whoop_vtx_hp. OpenVTx to provide firmware with both the SmartAudio and Tramp protocols. Either protocol can be used on the flight controller and on VTx power up the protocol used is automatically detected by OpenVTx. Main Features: OpenVTX firmware preload Smartaudio ready Nano size and stable power output Model:OVX306 Frequency:5.8G 48CH Transmitting Power:0//25mw/100mw/400mw Power supply:DC 5V Weight:2 without antenna Center distance of mounting holes:25.5mmx25.5mm Colour:As Shown Material:Plastic Package Contents: 1 * OVX306 Development module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.