This is the Futaba R6303SBE 3/18 Channel + S.Bus 2.4GHz FASST Speed Micro Receiver. This receiver is perfect for small park flyer aircraft, as well as electric helicopters with a main rotor diameter up to 1000mm when you need the benefits of S.Bus technology. 

Features

• S.BUS system output port with three conventional channel outputs
• Compatible with S.Bus and conventional system servos and gyros
• Automatic FASST 2.4GHz 7-ch mode or 8ch/10ch/Multi-channel mode recognition

Specifications

• Dimensions: 0.89 x 1.47 x 0.37" (22.5 x 37.4 x 9.3mm)
• Weight: 0.22oz (6.3g)
• Power Requirement: 3.7 - 7.4V (voltage range 3.5 - 8.4V)
• Antenna Length: 6 in