This is the 3300kV Pro4 Brushless Short Course Motor from Tekin. FEATURES: 4 pole 12 slot high torque design High RPM ABEC5 oversized bearings CMC machined 6061 T6 billet aluminum heatsink can Neodymium sintered magnets Designed to handle 2 and 3S LiPo batteries Dual plug sensor wire harness for use with all sensored and sensorless systems High purity copper windings for greatest efficiency INCLUDES: 3300kV Pro4 Brushless Short Course Motor with Sensor Wire REQUIRES: Electronic speed control such as the Tekin RX8, TEKM2300 SPECS: Weight: 6.75oz (193g) Shaft Dimensions: .60x .196" (15.3 x 5mm) Motor Diameter: 1.4" (35.8mm) Motor Length: 2.1" (52.9mm) Bearing Dimensions: Front: 5x13x4mm / Rear: 5x10x5 Turns: 2.5D jxs 09/21/11 ir/jxs