Safco Products 5138 Nylon 2" Glides for Apprentice II, Trenton, Precision, Office Stool, Task Master, sold separately, Black Optional 2" nylon chair glides Five 2" nylon glides, stem is 7/16 diameter by 7/8 of an inch in length, not including the stop at the base and 1 inch in length overall For use with Safco Products Apprentice II 7083BL and 7084BL, Trenton 3420, Precision 3401, 3380BL, 3390BL and Office Stool 5100, sold separately For use with Safco Products Task Master Chair Models 5117 and 5120, sold separately Easy installation