This is the HPI SF-10W Waterproof Analog Servo. FEATURES: Custom IC chip for high torque POM (polyacetal resin) gears for smooth operation Compatible with HPI receivers and all Futaba radio gear INCLUDES: HPI SF-20W Servo with Heavy Duty Horn and Instructions REQUIRES: Installing in vehicle and connecting to linkage and receiver SPECS: Voltage Range: 4.8 - 6.0V Torque: 36.10oz/in (4.5kg/cm) @ 6.0V Speed: 0.18 sec/60° @ 6.0V Length: 1.9" (47.8mm) Width: 0.79" (20mm) Height: 1.4" (36mm) COMMENTS: For replacement gears, order HPIM2786 For replacement Case Set, order HPIM4106 jxs 06/07/11 ir/jxs