Spektrum SR515 5 Channel DSMR Sport Receiver SPMSR515Spektrum SR315 3 Channel DSMR Sport Receiver SPMSR315 Built around frequency agile DSMR technology, the SR315 receiver delivers superb range and response, especially in noisy RF environments where a solid 2. 4GHz link is crucial. Not only is the 2. 4ghz link solid, this model also implements our lightning fast 5. 5ms frame rate, providing a quicker , low latency connection for the pro level enthusiast. The SR315 also features a new, modern case design