This is the Hitec HS-5086WP Waterproof Digital Micro Servo.
FEATURES: All metal gears with dual ball bearings
Programmable digital amplifier with MOSFET drive
Ideal for 1/8 - 1/14 scale cars and trucks and electric powered boats
INCLUDES: HS-5086WP Servo with 1.15" (29.4mm) Two Arm Servo Horn, 0.90" (23mm)
Four Point Horn, 0.67" (17mm) Round Horn and Mounting Hardware
SPECS: 4.8V 6.0V
Speed: 0.18sec/60° 0.15sec/60°
Torque: 41.66 oz.in (3.0 kg.cm) 50 oz.in (3.6 kg.cm)
Weight: 1.0oz (28.5g)
Dimensions: 1.22 x 0.60 x 1.22" (31.0 x 15.2 x 31mm)