This bell is very popular for adding an internal bell to a telephone that originally needed an external bell. Dealers often use them inside 200 series telephones or inside the French Bakelite model. I use them on the back of compact telephones etc. These have been out of stock for about three months but I have managed to get my hands on another batch. I am only selling 50 of this batch and keeping the rest for myself and so please if you need some get in quick.