Irvine Brush Set for 05 Cobalt Motor A highly efficient range of Cobalt motors in three basic sizes & with various winding options for each size (theres even a special Ducted Fan 480 motor). Each has a machined outer body, twin ball races, Samarium Cobalt magnets & resin impregnated windings for maximum performance & long life. The replacable Silver Graphite brushes have a high durability, if operated with the correctnumber of cells, & timing can be adjusted for optimising power against duration. Each motor is supplied with an aluminium propeller driver as standard. By using the information below, you can check the performance against your requirement & choose the correct motor accordingly. Ifyoure looking for that little extra performance without the cost of going brushless then try the new Irvine Cobalt motors, youll be surprised!