nitty gritty Speedplay Frog rebuilding - o rings

[eddief]

love the Frogs. new bearing kits from Speedplay are $37. those kits include bearings, o rings, and sealer for the pedals bodies. Enduro has the bearing kits for under $20, but those kits don't include o rings or sealer.

does anyone know if the o rings are anything special or should i be able to get those at any hardware store? and if yes, is there a way to know i am getting a good fitting replacement. just bring in the old one and try to match or is there a way to say "i need o rings in this specific size"?