The RP1 series of receivers are open source receivers based on ExpressLRS. Originally developed by Jye of the ExpressLRS development team, the Nano receivers utilize the ESP8285 MCU and the SX1280 RF chip.The RP1 has a UFL antenna socket for a full range antenna. The RP1 has built-in WIFI so you can upgrade the firmware over WIFI and configure the receiver via the built-in WebUl on your PC or cell phone. Thanks to its low latency and high refresh rate RF module, the RP1 is perfect for FPV racing or long distance racing. Thanks to the ultra- and nano-size for Whoops, drones and fixed-wing models, these receivers can be mounted almost anywhere! RP1 Specifications: Name: RP1 Nano Receiver Type: ISM MCU: ESP8285 RF chip: SX12801MLTRT Antenna: 65mm 2.4ghz T antenna Frequency Range: 2400 MHz to 2480 MHz Maximum Receive Refresh Rate: 500Hz/F1000Hz Minimum receive refresh rate: 25Hz Operating Voltage: 5v Firmware Version: ExpressLRS v2.4 pre-installed Firmware target: RP1/2 2400 RX Bus Interface: CRSF Material: PC+metal colour: as show Package Contents: 1 x receiver 1 x 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.