If you have an assortment O-Rings but you need a specific one. It's always difficult to measure their sizes.

This cone will help you to measure the inner size, the measures size go from 3mm to 22mm. And each corner can be used to measure width of the O-Ring.

So this cone can be used for O-Rings from :

• inner 3mm, outer 5mm and 1mm of diameter

to :

• inner 22mm, outer 29mm and 3.5mm of diameter