The RotorStar 6S 10A Super Mini S-BEC supplies a constant voltage to the receiver and servos in your model. ESCs that have a built-in linear BEC can easily overheat and thus lose efficiency when used in high performance applications such as 3D helicopters, this is due to the use of multiple high power digital servos which can draw a lot of current.

By using the RotorStar Super Mini BEC, you can ensure your model has the reliable and stable power that it needs.

Features:
• Compact size and lightweight
• 6V 10A output
• Wide input voltage range: 6~25.2VDC
• Dual output leads for extra security
• Over-current and over-heat protection functions
• Fully enclosed design makes the unit water resistant
• 90% or higher efficiency

Specs:
Input Voltage: 6~25.2V (2S~6S lipoly)
Output Current: 10A max
Output Voltage: 6V +/-0.1V
Working Temp: -20~65°C
Storage Temp: -10~70°C
Output Plug Type: JR style
Dimensions: 23x23x15mm
Weight: 30g

asking price 4k for 2

link of item: http://www.hobbyking.com/hobbyking/store/__33987__RotorStar_Super_Mini_S_BEC_6S_10A.html