Size: 1 Pack TWO SOUNDS: Classic two-note Ding Dong sound for the front door button and has an additional connection with a separate "Dong" for the rear or side door. DIMENSIONS: Cover: 8. 25 L x 5. 5 W Base: 6. 63 L x 4. 75 W COMPATIBILITY: Use with a 16-volt/10 VA or 16-volt/15 VA transformer (not included) when connecting to a regular doorbell. Search 16TR or "3TRAN" for a compatible transformer. QUALITY: Doorbell chime maintains a textured white modern finish. Easy to install to your doorbell button and doorbell transformer. PLEASE NOTE: If you would like to hear the sounds of the chime, please see the video that is with the images on the left hand side of this item page. PLEASE NOTE: If the chime is not working properly, the issue may or may not be with the chime. The issue could be with the doorbell button, transformer or the wiring. There are troubleshooting steps in the manual as well as on our website.