Get a more stable seat with this set of 4 ball feet made from VIBRAM rubber. 

Available in two sizes:

45mm fits:

• Chairs. Chair Zero, Chair Zero LT, Chair Zero L, Chair One Mini, Chair One, Chair One L, Tactical Chair One, Speed Stool M. 
• Tables. Table One, Table One Hard Top, Tactical Table One, and Tactical Table One L.

55mm fits:

• Chairs. Chair One (re), Chair One Highback (re), Chair One XL, Sunset Chair (re), Tactical Sunset Chair, Savanna Chair, Swivel Chair, Bench One.
• Tables. Table One, Table One Hard Top, Table One Hard Top L, Tactical Table One, Tactical Table One L,
• Cot Accessories. Cot Leg 12 pcs, and Cot Leg 16 pcs.