The Wirepath Rubber Grommets are compatible with the 30" and 42" plastic enclosures. There are (3) 1-3/4" openings on each end of the enclosure that these can be installed for additional protection once the knockout is removed.
Features
10 Rubber Grommets Included: There are 10 rubber grommets included in each package so you have plenty of protection to work with.
Complete Protection: Rubber grommets attach to (3) 1-3/4" openings on each end of the enclosure for additional protection once the knockout is removed.