Dust cover for cables

Anyone have a good source / method for capping the ends when I do not have the units mounted? Boat stays on a slip so we take the electronics off each time but I'd like to not have the cable ends exposed to elements/bugs etc. when not in use.

Quick wrap with a plastic like Reynolds wrap would be cheap and easy.

Obviously depends on the brand, but Home Depot carries some rubber caps that slip on. Typically bears the bolts/screws, in the specialty drawers.