Get a more stable seat with this set of 4 removable ball feet. Available in two sizes; 45mm is compatible with Chair Zero, Chair Zero LT, Chair Zero L, Chair One Mini, Chair One, Tactical Chair One, Speed Stool M, Table One, Table One Hard Top, Tactical Table One, Tactical Table One L, Cot Leg 12 pcs, and Cot Leg 16 pcs. 55mm is compatible with Chair One (re), Chair One Highback (re), Chair One XL, Sunset Chair (re), Tactical Sunset Chair, Savanna Chair, Swivel Chair, and Bench One.