The Maclan MRR V3 Competition Sensored Brushless Motor is the result of the latest efforts by Maclan Racing and is based on the successful V2 platform with various updates to improve overall performance. Improvements in this generation are significant and will make a noticeable performance gain. Features: Engineered & Developed right here in the U.S.A. Updated 1-piece precision machined motor can design that eliminates the need for long motor can screws. Redesign uses a total of 5 short screws. It saves weight and no more optional screws required. Improved stator shape that meets the latest ROAR regulations for the highest legal performance. Realigned sensor positions for more accurate reading. Premium Ultra High Torque Rotor is now standard by default. You get best performance right out of the box. Available in 13.5, 17.5, 21.5 Turns Specifications: Available Turns: 17.5 Short Stack: Yes Case Length: 51.20mm Case Diameter: 36.00mm Shaft Extension: 14.00mm Shaft Size: 3.17mm Weight: 147g±2g Screws Size (end cap): M2.5x6 (1.5mm Hex) Screw Size (motor can): M2x6 (0.05" Hex) Front Bearing Size: ID: 3.175mm OD: 9.525mm H: 3.9675mm Rear Bearing Size: ID: 3.175mm OD: 7.9375mm H: 3.5712mm Poles: 2-Pole Default 13.5/17.5/21.5 Rotor: Premium Ultra High Torque Rotor ROAR Approved: 17.5 Approved 13.5/21.5 pending approval Limited Factory Warranty: 120-Day