Fitment: Suitable for tractor and trailer brakes, any heavy duty brake works great ! Offers original equipment performance at competitive price. Function: Make easy install spring on the s-cam air brake, simply hook the retaining spring loop and press down. Material: Crafted from quality & heavy duty steel, sturdy and wear resistance to ensure great performance and long-term service. Easy to Use: This tool makes install spring on the S Cam Air Brake a snap. No more using vise grip and screwdriver to remove brake shoes.Simply hook the retaining spring loop and press down against the axle. .