All the features of 276 are included in Midmark 277 Air Stool with added support of a backrest. You will have an all-day relief thanks to the wide and padded seat constructed from dense foam along with contoured backrest which keeps you relaxed. The Beadless upholstery seam will not dig in to your legs The glides helps to keep the stool stationary while the pneumatic adjustability allows the stool to integrate with any room