The Carlon RC3304F wireless doorbell is a Carlon designer series door chime. This doorbell is most noted for exceptional sound quality & decorative design that rivals even a wired doorbell. It boasts a 4″ high quality speaker that produces a crisp, pleasing, distinguishable ring. Most top selling doorbells have very small speakers less than 2″ which tends to distort the sound especially at mid-high volume. As far as design, top selling units are extremely drab, cheesy & generic looking. The RC3304F’s design is suitable for any type of home from traditional to extravagant – tastefully designed white chime cover paired with faux brass side tubes One major advantage of this door chime is that it’s compatible with other Carlon wireless chime push button doorbell & door chime receivers (see below) allowing different style selections, color and receiver types (both battery operated & plug in) to compliment this unit. Unlike other wireless doorbells for home, you’re not limited to the number of push buttons & chime receivers you can use as long as they are in range. This unit can be used as a portable chime (both push button and receiver not mounted) or mounted semi permanently (double sided tape,) or permanently (screws, liquid nail type adhesive) This wireless doorbell operates simply with no confusing or complicated programming: 1. Place 4 alkaline D cell batteries (not included) into brass tubes by following instructions 2. Push button (2) CR2032 lithium long life batteries are installed. Simply select 1 of 13 melodies by pressing once on the small raised button located on top of button. Receiver will play next selection. Technical: 1.13 Ringtones 2.4″ Premium Sound Speaker 3.Wireless Doorbell Operating Distance: Up to 150′ line of sight 4.Adjustable sound; Low (70db) Med (80db) High (97db) For Optimal Service: 1.Keep the button away from metal, Low-E glass & concrete walls 2.Wireless doorbell range depends on the push button & receiver location.