The stock size of the center cap on our rims is 1/8" X 6.5 ID / 6.75 OD and is a standard ANSI #260 O-ring.
You can buy replacment o-rings through Grainger - P/N 1KLJ9
$14 for a pack of 10.
You can buy replacment o-rings through Grainger - P/N 1KLJ9
$14 for a pack of 10.