Spektrum DSMX SRXL2 Remote Serial Receiver with Telemetry SPM4651TSpektrum DSMX SRXL2 Remote Serial Receiver with Telemetry SPM4651T The SPM4651T DSMX SRXL2 Serial Micro Receiver takes the original SPM4649T receiver and adds more value, functionality, longer control and telemetry link range. The SPM4651T uses our feature rich SRXL2 protocol to give pilots a blazing fast serial data connection with up to 20 channels. SRXL2 is a powerful and open source communication protocol developed by Spektrum. It greatly improves