Wiring Grommets are made from a nitrile based rubber compound and are generally flare or collared on each side. These grommets are generally used in car firewalls or cabinets to run electrical cables through which generally mean they are designed to fit a wall thickness of 1.6mm. 

The hole size advise is the outside hole in which the grommet will sit in, while ID size is the size of the cable which will run through. 

We have a variety of sizes to choose from which can be purchased individually or in packs of 25, we also offer multi-buy pricing. The more you buy the more you save.