This is the Futaba R6303SB 3-18 Channel FASST 2.4GHz S.Bus Micro Receiver.

Features

• Works with conventional servos as well as S.Bus system compatible servos and gyros
• High-speed or normal operating mode
• The receiver recognizes the signal mode (FASST 2.4GHz 7ch mode or 8ch/10ch/Multi-Channel Mode) automatically after linking
• One year limited warranty

Specifications

• Power Requirement: 3.7-7.4V, Usable voltage 3.5-8.4V
• Dimensions: 0.89 x 1.47 x 0.37 in (22.5 x 37.4 x 9.3 mm)
• Weight: 0.25 oz (7.2 g)
• Antenna Length: 6 in