Wheel Cap O-Rings

[esenior]

I've got a set of Colorado Custom wheels on my Camaro and I'm missing a couple of the o-rings that hold the center cap on. Talked to Co Custom today and they want $5 per o-ring and another $7 for shipping. I thought this was ridiculous. Does anyone know what size these o-rings are? Anywhere else I can get these? Need a set of 8 (also have Co Custom wheels on my Chevelle). Thanks...Eric