Sit-stop castors, pack of 5, for hard floors, for high chairs. Supplied = assembled. Alternative to fixed floor glides. Mobility in high workplaces. Sit-stop castors: stop when under load, moving when not under load. Soft sit-stop castors for hard floors: stop when under load, moving when not under load. For safety reasons, high chairs with a seat height of 650 mm or more may only be equipped with sit-stop castors due to the risk of tipping over.