These large 3" casters are for use with our 1½" tube furniture such as our TV Table, A/V caddies and A/V Towers. They add 3½" to the height of your product and have non marking rubber wheels. These large casters add mobility and flexibility to most of our tube frame pieces and can hold up to 400 lbs. Set of 4 (2 locking & 2 non-locking).