Frequency: 915 Mhz Chip type: ESP8285 MCU RF chip: SX1276 Minimum refresh rate: 25Hz Maximum refresh rate: 500Hz ELRS project is an open source project, so as long as the use of ELRS this protocol HF head, regardless of brand, can be mutual frequency pair, but to meet three conditions; One: the frequency should be the same, the same 915MHz; Second, the firmware version should be the same, for example, if the HF head brushes the 1.1 firmware, then the receiver should also brush the 1.1 firmware; Third, no frequency password, or have set the same password. Input voltage:3.6V-5.5V Antenna interface:ipex1 Weight:6g (receiver only) Depending on the batch, the appearance and color of the product , but this does not affect use. Colour: Material:Metal+Plastic Size:11x18x3MM Package Contents: 1 * Receiver (with 1 antenna) 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.