The RF-11 receiver is a 2-channel 2.4GHz radio receiver designed for use with the TF-11 2.4GHz radio transmitter from HPI Racing. Use it as a replacement part for lost or damaged receivers, or as a way to use multiple cars with one transmitter.2.4GHz high frequency reception Uses the latest digital FHSS (Frequency-Hopping Spread Spectrum) technology Long range reception Programmable failsafe lets you set neutral point for electric cars or full brake point for nitro cars if radio reception is lost (HPI always recommends a throttle return spring for nitro & gas-powered cars)Use with the #105406 TF-11 radio transmitter.