Futaba R7301SB 1-Channel (PWM) Air Receiver FASSTest

This is the 

1-channel PWM, 26-channel S.BUS/S.BUS2 FASSTest, Dual-Link receiver, up to 8.4V, with telemetry and dual high gain antenna diversity.

Specifications
Protocol: FASSTest
Command Protocol: PWM, S.BUS, S.BUS2
PWM Channels: 1
Dimensions: 39.5×21.5×6.5mm
Weight: 6 g