3/8″ OD x 1/4″ ID x 1/16″ will fit the cell’s nozzle and provide the needed seal to prevent slow overnight deflation. See my post on QA for a Select Comfort bed – if I’d spotted the missing O-ring first, it would have cost me 79 cents to fix the problem instead of $300.79.

I do have a nice portable full-size air mattress that fits into a standard Rubbermaid storage bin now, so it wasn’t a complete waste, but better to save someone else the money!