Board width 50mm, thickness 4mm, maximum range 40-70mm Function: This brake piston compressor wrench is mainly used for pushing back brake piston, replacing brake pads, repairing and installing car brake cylinder, it is an essential car gadget for garage and personal repair , very practical. Material: Our brake piston compressor wrench is made of carbon steel, which is strong, corrosion resistant and sturdy. There is a rubber sleeve on the handle, easy to use, comfortable in the hand, not easy to fatigue for a long time, and improve work efficiency. Wide Fit: Perfect for most brake caliper ratchets, four-piston calipers for trucks and commercial vehicles equipped with dual and four-piston fixed calipers or single and dual-piston floating calipers. Please note that this ratchet saddle spreader "pushes back" the piston, it cannot twist and compress at the same time, which is necessary for some brakes. Professional Tool: This heavy-duty carbon steel brake caliper press is designed for adjusting automotive brake pumps. Working range 40 - 70 mm. Comes with 4 S-type brake pad replacement hooks that allow you to replace car brake pads more easily.