If you live in a climate with a lot of rain, snow, sleet and hail, you may want to keep a couple of these in your glove box When your antenna isn't in the mount you can screw one of these plugs in an keep the "nasty's" from making a new home Also great for those who take their vehicle though the carwash Fits any 3/8"-24 threaded mount or accessory Each Package contains 2 plugs PLG-1 3/8 Inch 24 thread protector plug