Easily clean out and inspect the inside of your bird houses with this Threaded Cleanout Access Cylinder and Screw-On Lid. Nest checks become a breeze! Add to any 8″ or larger gourd. Just use a hole saw to drill a 4-1/2″ hole in the gourd, or cut it out with a jigsaw. May need some slight sanding to fit properly. Use adhesive caulk to secure the snug-fitting cylinder in the gourd. Caulk sold separately.