The motor is suitable for 1/10 rc Trail Crawler car HSP HPI Wltoys Kyosho brushed TRAXXAS trx-4 trx-6. It has long-lasting performance with virtually maintenance-free operation.<br/>Features:<br />Motor size: 550, 3.175mm output shaft.<br />Virtually maintenance-free operation and long-lasting performance.<br />Integrated cooling fan pulls cool air through the motor to keep temperatures down. Heat-resistance running motors allow faster speeds, longer runtime, and extending motor life.<br />Precision balanced rotor, smoothness for best reliability and maximum RPM.<br />Suitable for 1/10 rc Trail Crawler car HSP HPI Wltoys Kyosho brushed TRAXXAS trx-4 trx-6.<br/>2 types optional:<br />550 21T Brushed Motor<br />Size: 550<br />Turns: 21T<br />Watts: 91W<br />Max voltage: 6-8.4V<br />Max Amps: 48A<br />IO: 1.4A<br />Resistance: 0.0043<br />KV(RPM/Volt): 21T<br />Max RPM: 12900<br />Diameter: 36mm<br />Length: 55mm<br />Length of extending Shaft: 11mm<br />Shaft diameter: 3.175mm<br />Weight: 231g<br />Package weight: 233g<br />Package size: 7.5*4*4cm<br/>550 29T Brushed Motor<br />Size: 550<br />Turns: 29T<br />Watts: 71W<br />Max voltage: 6-8.4V<br />Max Amps: 39A<br />IO: 1.4A<br />Resistance: 0.0043<br />KV(RPM/Volt): 29T<br />Max RPM: 10500<br />Diameter: 36mm<br />Length: 55mm<br />Length of extending Shaft: 11mm<br />Shaft diameter: 3.175mm<br />Weight: About 231g<br />Package weight: 234g<br />Package size: 7.5*4*4cm<br/>Package list: 1*RC 550 motor