JR Propo S8711BL Brushless 2K Servo Alloy Case, Metal Gear, xBus
Specifications: 
@6.6V 29.3kg-cm    Speed: 0.13 sec/60゜
@7.4V 31.7kg-cm    Speed: 0.12 sec/60゜
@8.4V 36.00kg-cm    Speed: 0.10 sec/60゜
Weight: 79g
Dimensions:  36.5mm x 20.5mm x 40.0 mm