The Heavy Duty Plate Casters come in a pack of 4, including 2 swivel and 2 rigid casters, and can hold up to 2800 pounds, making them perfect for transporting heavy loads. These casters are made of Polyurethane Mold on Steel and come with a roller bearing with hardened raceway for extra strength. The top plate measures 4"x4-1/2" and has mounting over heights of 5-5/8". The swivel casters can rotate 360 degrees, providing greater maneuverability. With a green color and easy plate mounting, these plate casters are perfect for a wide range of applications. Additionally, the product comes with a 90-day hassle-free return policy for all products purchased, along with a 100% satisfaction guarantee.