Futaba 4GRS 4-Channel 2.4GHz T-FHSS Telementry Radio With R304SB Receiver Published by admin on January 19, 2024 4GRS Transmitter – 4-Channel Digital Proportional RC System. The sensitivity of Futaba car rate gyros can be adjusted from the T4GRS. Frequency channel setting is unnecessary: Channel shifting takes place within the 2.4 GHz band automatically.