Ambulatory Walker 4&#34; Casters WHITE - 4&#34; CASTERS - SOLID VINYL by Mjm International Corp. $219.00. Heavy-duty casters provide added weight, for better balance.. Height adjustable from 32Â½&#34; to 35Â½&#34;.. Unique frictionless locking security gate system.. Allows residents to ambulate safely.. Seat Height: 21&#34;.. Bridges the gap between wheelchair and walker - aids in walking and provides a seat for rest.