Why you want this motor? Compliant with roar and IFMAR rules The use of a heat-resistant magnet attached aluminum case and double insulated windings, high precision bearings, and rotor with a strong structure guarantee outstanding performance and Super durability. The built-in Hall sensor Non-Adjustable end bell combined with a high precision and balanced rotor guarantee the user a smooth and linear power on demand. The silicone O-ring seal fitted between the end bell and stator helps to conduct inner heat to the motor case and prevent dust from entering the Hall sensor. The detachable structure design for daily cleaning and maintenance Can effectively prolong the service life of this JUSTOCK motor and improve its operating efficiency. Perfectly matched with the xr10-justock ESC for all zero timing Spec racing and also compatible with other HobbyWing electronic speed controllers including other brands. Battery: 2s-3s lipo 2 pole 1/10, 1/12 On-Road (Truggy/ drifting car/ F1/ monster) & Off-Road (Buggy/ 2WD SC truck/Truck) stock/ sport race (choose the motor base on competition rules.) FREE/casual run for new beginners. Rock crawler (21.5T, 25.5T only) JUSTOCK combo (esc+motor) available