These fit into a 7/8" panel or wall hole having a maximum material thickness of 1/4". The grommet is designed to be slightly snug on the threads for better weather protection.  The grommet will center the feed through in the 7/8" hole. The heavy duty washers are designed to be slightly loose on the feed through's thread to prevent marring of the thread. The material hardness of the grommet is 55A on the Durometer scale and it is made of rubber. The outer diameter of the grommet is 1-1/8" and the thickness is 1/2". The washers are a heavy duty zinc plated steel having a outer layer of zinc that helps protect the inner steel and are slightly larger than the grommet to help protect the grommet. Approximate thickness or space used on the bulkhead is just slightly under 1" so plan accordingly on your length of your bulkhead connector.

You get (1) grommet, (2) Heavy Duty washers and (2) standard series nuts in each kit. (This does NOT come with the feed through connector shown).

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