Use only wheel types that are recommended for your power tool and the specific guard designed for the selected wheel. The grinding surface of centre depressed wheels must be mounted below the plane of the guard lip. The guard must be securely attached to the power tool and positioned for maximum safety, so the least amount of wheel is exposed towards the operator. Wheels must be used only for recommended applications. Always use undamaged wheel flanges that are of correct size and shape for your selected wheel. Do not use worn down wheels from larger power tools.