Unbeatable value for ergonomic, quickship, lifetime warranty. Comfort and support result from the four-inch thick, high-resiliency, molded foams used in the seat and back. Select from among the five control fuctionality options and add a seat slider for variable seat depth. Add from one of the multiple arms choices including fixed and adjustable arms. Choose from two back heights. Drafting stools in one of two heights are also available in the Logic series.