This is the CC BEC 10A Receiver Battery Eliminator by Castle Creations.

FEATURES: Eliminates the need for a receiver and servo battery pack
Draws higher voltage from the motor batteries and drops it to a
voltage level suitable for the receiver and servos

INCLUDES: One CC BEC receiver battery eliminator

REQUIRES: Installation in the aircraft

SPECS: Length: 1.2" (30mm)
Width: .6" (15mm)
Height: .4" (10mm)
Weight: .4oz (11g)
Input voltage: 5V to 25.2V (2S to 6S LiPo)
Current output: 10A Peak
Selectable Output: 4.8 - 9.0V