Built-in TCXO (temperature compensated crystal oscillator) Default firmware shipped from the factory: Unified ESP32 2400 RX Can be upgraded to EP1 Dual 2400 RX3.0 FW Type: ISM2.4GHz ESP32 D4, dual SX1280 (SX1281) Antenna connector: MHF 1/U. FL frequency: 2.4GHz (2400~2480MHz) Telemetry power: Greater than19dbm Receiving protocol: CRSF Input voltage: +5V DC @"+"pad PCB size: 19mm x 14mm Due to different batches, there may be differences in the appearance, color, and printing of the product, which not affect its use. Material: PCB colour: Package Contents: 3 x EP1 DUAL TCXO Receiver 6 x T-shaped antenna 3 x Heat shrink tube 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.