This is a Hitec HS-81S Micro Servo. These are great for small electric planes, helis, and small cars. This has the universal connector that works with JR, Hitec, Futaba, and Airtronics, and also works with some micro RTR vehicles (check with manufacturer of micro car for compatibility).
FEATURES:Compact, Lightweight Design-Ideal for Electric cars, airplanes, and sailplanesStrong, Dependable Gear TrainHigh Torque and High SpeedMounts with Two Screws
INCLUDES:One HS-81S Micro Servo with 6-3/4" connector wire.One 7/8"x7/8" X-shaped servo hornOne 1-1/8" long straight servo hornTwo brass eyeletsTwo mounting screwsTwo servo grommetsOne servo horn screw
SPECS:Transit Speed: 0.11 sec/60deg at 4.8V 0.09 sec/60 deg at 6.0VOutput Torque: 36.10 oz/in at 4.8V (2.6kg/cm) 41.66 oz/in at 6.0V (3kg/cm)Length: 1.17" (29.8mm)Width: 0.47" (12mm)Height: 1.16" (29.6mm)Weight: 16.6g (0.58oz)Mounting holes on-center: 1.31"(33.27mm)