The metal D-645MW is part of our D-Series dynamo servo line.

All Hitec D-Series servos have been designed using our brand new, cutting edge, custom engineering.
Combining industry leading high-resolution, state-of-the-art ultra-response technology with a 32-bit MCU and 12-bit ADC for unprecedented programmability and flexibility, these servos deliver significantly smoother movement.
The speedy, powerful line operates on a wide 4.8 ~ 8.4 voltage range, allowing use with any common battery chemistry without the need for adapters or regulators. Featuring Hitec's industry standard 25-tooth output spline with 3 mm hex screw, each D-Series servo brings monster performance never known before in the market.

Specifications
Motor Type: Coreless
Bearing Type: Dual Ball Bearing
Speed (4.8V / 6.0V / 7.4V): 0.28 / 0.20 / 0.17 sec/60º
Torque oz-in (4.8V / 6.0V / 7.4V): 115 / 158 / 180 oz-in
Torque kg-cm (4.8V / 6.0V / 7.4V): 8.3 / 11.4 / 13.0 kg-cm
Size in Inches: 1.59 x 0.77 x 1.48 in
Size in Millimeters: 40.6 x 19.8 x 37.8 mm
Weight oz: 2.11 oz
Weight g: 59.8 g