This is the HS-5665MH High Speed, High Volt Metal Gear Servo from Hitec.

FEATURES: Designed to be powered from a 2-cell 7.4V LiPo battery for extra
speed and power
Ideal for 1/10 to 1/8 scale on- and off-road vehicles, larger sport
helis and large scale aerobatic aircraft up to 25%
Programmable features include; Dead Band Width, Rotation Direction,
Rotation Speed, End Points/Neutral Points, Fail Safe On/Off, Fail
Safe Point, (requires Hitec programmer HFP20, HPP20 or
HPP21 HRCM4420)
Heavy duty metal gear train (MK first gear)
Three pole ferrite 7.4V optimized motor
Dual ball bearing output shaft

INCLUDES: HS-5665MH High Speed, High Volt Metal Gear Servo with Connector,
0.94" (24mm) round horn, 1.8" (45mm) round horn, 1.7 (44mm) 4-
point horn, 0.98" (25mm) single arm horn, 2.3" (59mm) double arm
horn, 0.87" (22mm) aluminum single arm horn, mounting hardware and
instruction sheet
REQUIRES: Installing in model and connecting linkage

SPECS: Motor Type: Three pole ferrite (7.4V wind)
Bearing Type: Dual ball bearing
Speed: 6.0V, 0.16 sec/60°
7.4V, 0.14 sec/60°
Torque: 6.0V, 122 oz-in (8.8 kg-cm)
7.4V, 139 oz-in (10 kg-cm)
Size: 1.6 x 0.8 x 1.5" (41 x 20 x 38mm)
Weight: 2.1oz (60g)