If you have an unused hole from a previous antenna (or whatever) use one of our snap in hole plugs to seal it up. The HPA-S (small) hole plug package holds 2 plugs for 3/8" holes and 2 plugs for 1/2" holes.
(2) Plugs will fill in 3/8" Holes
(2) Plugs will fill in 1/2" Holes