Power HD WP23KG Standard Size servo. FEATURES: Blue & black casing with middle aluminum case with plastic top and bottom Specs: Torque(4.8V): 250.0oz/in (18 kg-cm) Torque(6.0V): 319.4oz/in (23.0 kg-cm) Speed: 0.14 sec (4.8V)‚ 0.12 sec (6.6V) Operating Voltage: 4.8 ~ 6.6 DC Volts Weight: 75 g (2.65 oz) Bearing Type: Ball Bearing x 2 Motor Type: Coreless Motor Gear Type: Titanium & Steel Working frequency: 1520μs / 333hz Size: 40.7 x 20.5 x 38.5 mm ( 1.60 x 0.80 x 1.49 in) Servo arm type: Futaba Note: When the digital steering gear is subject to resistance will be issued a continuous creak current sound, the greater the resistance sound the more loud, this is a normal phenomenon. Not for use underwater.