Flush mount as a gasket

[YJSONLY]

What are yall using/making for the flush mount as far as gasket? the ones I bought (ebay) didn't come with anything.

 

[DSL_PWR]

Permatex has a gasket maker. I used that on the first set of Lifetime LED's I got.

I recently got some Rigid lights and I think the gasket I made with permatex was better than the gasket that came with them.