Nice working brass bell mini ringer type 2554.  

                                                 Use for your projects.  Made by ITT New Old Stock

 One of the best ringers made to use if you need your telephone to ring. This is the easiest and most economical way to add a ringer to your old telephone. Instructions come with this.

Dimensions 3 1/2 x 2 x 1 1/4 inches. Comes with paperwork.