Am using these plugs to cover some 1/2" drilled holes on concrete (I used a hammer drill and a 18" long drill made for concrete/masonry to do a number series of holes 3" away from my foundation and 12" spaced apart from each other) I poured Termidor SC per instructions provided and video help from Do my Own. Plugs fit nicely not loose or tight, just snug. It all depends how steady you are when drilling those holes, if you keep moving around your drill trying to get in a good position you will ending up making the hole slightly larger causing the plug to fit kind of loose (plug does not fall all the way in, but is not snug any more). After pressing down the plug about 1" deep I filled in with DAP silicon for concrete applications which is waterproof as it claims. If I need to reapply Termidor SC will be as quick and easy as a breeze. Time will tell how long they will last. I am happy with the purchase. 50 pcs for $10.00 great deal.

These plugs save my a lot of time by not having to stuff paper in the holes and fill with liquid cement which eventually dries into an indentation. Put the plug in and tap with a screw driver and move on to the next hole.