The red hub end fits tight on the blue spigot end and holds the whole thing together without having to use any kind of glue or mechanical fastener. If you cut the hole in your bucket precisely the whole thing will be tight and won't move. I guess you could say that the hub pushes the bucket material tight on the curve of the spigot and holds it. Dang it Jimmy I don't know how else to explain it, just do it and see what results you get. If it doesn't work to your liking you can always take it apart and reuse some of the pieces, you would catch heck doing that if you had of glued it on.