Zinc Plated Fabricated Steel Fixed Gate Castor Spring Loaded Side Plate Fixing 100mm 65 Shore A Blue Elastic Rubber Tyred Wheel With Black Nylon Centre Ball Journal Bearings Spring Compression Starts At 20kg Compression At 75kg Is Approx 48mm Reach Compliant Also Pah-Free Rubber To Confirm To Eu-Directive 2005/69/Ec