What do you mean two sets of holes one at 2 inches and one at 2 1/2 inches I need the diameter of the insert and how high the hole is from the wheel for pin? Not in millimeters but in inches I’m in America.
We recommend this one:https://www.vevor.com/stem-caster-c_10474/5-swivel-caster-with-dual-locking-scaffolding-round-stem-steel-replacement-p_010374936492