This is the HS-M7990TH Digital, Monster Torque, Programmable Servo from Hitec.

FEATURES: High linearity semi permanent magnetic rotary encoder 2 cell LiPo and 6 cell NiMH compatable Durable titanium alloy metal gears Dual ball bearing 12bit high resolution circuirty Programmable G2 digital amplifier with MOSFET drive (separate servo programmer sold separately) Ultra hardness gear shaft 4 axial metal bushings Heat sink for motor and MOSFET Water and dust resistant

INCLUDES: One HS-M7990TH servo One small aluminum single arm servo arm One small black double servo arm One medium black double servo arm One large black double servo arm One black large single servo arm One round servo horn Four rubber grommets Four brass eyelets Four 2x16.3mm mounting screws

REQUIRES: Installing in model and connecting to control linkage and receiver

SPECS: Speed: 0.21 sec/60 degrees @ 6.0V 0.17 sec/60 degrees @ 7.4V Torque: 36.0 kg-cm (500 oz-in) @ 6.0V 44.0 kg-cm (611 oz-in) @ 7.4V Weight: 79g. (2.78 oz.) Dimensions: 43.8x22.4x40mm (1.72x0.88x1.57in) lmm 7.14.10  

BOX DIMENSIONS: 3.00" W. X 1.88" H. X 4.00" L. BOX WEIGHT: .37 LBS.