If you are a sport boater or top notch racer on a budget, the Maytech motor is the Brushless motor for you! Maytech high performance brushless motors have the rpm and motor efficiency similar to that of Brushless motors like Hacker that are 2 to 4 times higher in Price! The Maytech motor is a far better motor. It runs cooler because its far more efficient and much better balanced. It also comes with a 6mm drive shaft that has a 5mm output shaft to fit all the popular 5mm couplers. Motor Specs: 12-32 NiMh or 4s to 8s Lipo cells in a 30"- 40" mono or hydro. 1400 - 1800 Watts Maximum with proper cooling. 36mm Diameter x 60mm long 5mm Output Shaft for use with 5mm Couplers. 25mm Mounting Hole Spacing. Uses 3mm screws. 333 grams 2-Pole Neo Magnets & Compressed Windings. Dimension: 36mm (dia) * 60mm (L)