RC4WD 540 Crawler 20 Turn Brushed Motor. 

Features:

• Custom Made 540 Steel Case

• Chrome Plated Case

• Build in Capacitor for Minimizing Glitch

• High Torque Magnet and Rotor

• Small Footprint (50mm long)

• Tuned for Rock Climbing and Scale Driving

• Polished Bushings

Specifications:
Body OD:1.39in / 35.5mm
Length:1.96in / 50mm
Output Shaft Length:0.43in / 11mm
Output Shaft OD:0.12in / 3.1mm
Min and Max Voltage Range:2.4V-30V
Weight:5.5oz / 156g
(At No Load) RPM @ 7.2V:20000 +10% , 2Amp Current
(Rated load) RPM @ 7.2V:18400 +10%, 7.92Amp Current
Designed Operating Temperature Range:-10°C to +60°C
Shaft end play:0.1mm to 0.5mm
Noise Level:< 78DB