1. Disc brake adjustment disc is made of high quality stainless steel material.It is extremely durable and reliable. 2. Make sure the bicycle brake tool is clean and do not oil pollute the disc. 3. Brake Rotor Spacer Tool is very practical and simple disc brake adjustment tool, easy to adjust and high efficiency. 4. Use to keep the distance between the adjustment sheet and the disc parallel in the same direction to symmetry the movement of the left and right clamp piston to avoid the piston being too noticed. 5. Disc brake adjustment tool is suitable for various disc brake adjustment.