With the SL-6153, the volume of the chime is adjustable, and you can select one of three different chimes, and the two-inch magnetic speaker gives you a rich, true-sounding tone. You can select from 128 code settings (which allow the doorbell to communicate with the chime) to make sure your neighbor's wireless systems won't set of your chime.
The battery for the doorbell is included, along with all the mounting hardware you'll need. Note that you will have to supply three D batteries for the chime.--Josh Dettweiler
What's in the Box
Doorbell chime, doorbell button/transmitter with battery, hardware pack