Great attachment
I was worried that there would be a lot of noise or key rattle but theres none! They have concave washers that keep the key tight so it doesnt rattle or come out unless you want it to. If you dont have 3 keys you use, you will need to remove the additional pucks and store them away or they will rattle. It will not work with keys that dont have the hole centered horizontally or have a very large grip, but standard house and mailbox keys fit just fine.