JR Propo S3411 Servo. XBus. 
(Competition Version has Alloy upper case)
Specifications:
@ 6.6v 5.9kg-cm 0.18 sec/60deg
@7.4v 6.6kg-cm 0.16 sec/60deg
@8.4v 7.5kg-cm 0.14 sec/60deg
Weight: 30 grams (Competition 32 grams)
Dimensions: 26.5mm x 15.0mm x 33.0mm