【Perfect fit】Applicable to RS550, the carbon brush with support ensures the fit and stable operation.Please make sure it fits your engine before buying. 【Efficient Use】Works with good reliability at high speed, the carbon brush motor also achieves high working efficiency. 【Extended Lifetime】 Worn brushes are often the cause of a malfunctioning motor.Replacing the brush holder will extend the life of your power tool and restore performance to its original state. 【Premium Material】Application of premium quality ABS and aluminum alloy provides excellent durability for long time use, ideal replacement for your old or used part. 【Wide Use】It can be widely applied to driver, electric drill, electric screwdriver and many other tools, very useful.Designed to be compact in size and light in weight, installation can be completed quickly.