RadioMaster 2.4GHz RM 4IN1 Transmitter External ModuleThe RadioMaster 4IN1 external module is a multi protocol module that integrates CC2500, NRF24L01, A7105 and CYRF6936 RF chips. Designed for OpenTX and EdgeTX systems, the RM 4IN1 module allows the radio to connect with most mainstream protocols on the market. Features Up to 20dBm power output Compatible with more than 70 RF Protocols Wireless trainer function For Zorro, Boxer, TX16S MKII, TX12 MKII and more Specification Item: RM 4IN1 Module