This is what I found about them
Detailed Specifications
Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 3.3-7.4 Volt Peak to Peak Square Wave
Operating Voltage Range: 4.8-7.4 Volts
Operating Temperature Range: -20 to +60 Degree C (-68F to +140F)
Operating Speed (6.0V): 0.15sec/60 degrees at no load
Operating Speed (7.4V): 0.12sec/60 degrees at no load
Stall Torque (6.0V): 333.29oz/in. (24kg.cm)
Stall Torque (7.4V): 416.61oz/in. (30kg.cm)
Standing Torque (6.0V): 433.27oz/in. (31.2kg.cm) 5 degree deflection
Standing Torque (7.4V): 541.59oz/in. (39kg.cm) 5 degree deflection
Operating Angle: 90 Deg. one side pulse traveling 400usec
360 Modifiable: Yes
Direction: Clockwise/Pulse Traveling 1500 to 1900usec
Idle Current Drain (6.0V): 3mA at stop
Idle Current Drain (7.4V): 3mA at stop
Current Drain (6.0V): 300mA/idle and 4.2 amps at lock/stall
Current Drain (7.4V): 380mA/idle and 5.2 amps at lock/stall
Dead Band Width: 2usec
Motor Type: Coreless Metal Brush
Potentiometer Drive: 6 Slider Indirect Drive
Bearing Type: Dual Ball Bearing MR106
Gear Type: 4 Titanium Gears
Connector Wire Length: 11.81" (300mm)
Dimensions: 1.57" x 0.78"x 1.45" (40 x 20 x 37mm)
Weight: 2.18oz (62g)