This is a slide-type extension glider compatible with the new (current) model of the Tripp Trapp. When attached to the legs of the Tripp Trapp during the use of the Newborn Set or Baby Set, it prevents the Tripp Trapp from tipping backward, providing greater stability. I have used it for about 4 years. There are some minor scratches and signs of use, but it is in relatively good condition. Please understand that this is a used item before purchasing.