All of our grommets are designed to fit standard panel holes ranging from 3/16” to 2-1/2” in imperial sizes and in the key metric sizes. The grommets easily snap into the holes without any tools. When selecting a grommet, you should consider the environment exposure that they will see. In most cases, rubber grommets are just fine, but if chemicals, ozone or UV exposure are a concern, then one of the PVC or TPR grommets would be a better match for your application. In other cases, a plastic grommet or a nylon version can be selected as they are also a stocked item. Beyond standard grommets, we offer numerous specialized styles including grommet sleeves, diaphragm grommets, IP67 grommets and edging grommets to meet the demands of your application.