Features 1、Easy for installation and no need for wires. 2、1 remote button and 2 plugin receiver, you can install the receiver in two different places. 3、Including 32 melodies, you can enjoy melodies whenever someone rings at your door. 4、With LED light flashing when the doorbell ringing, remind the elder who can’t hear and hearing-impaired to know that the doorbell is ringing. 5、Press the select tone button in the receiver to change the ringtone. Specification Features: 1. Easy for installation and no need for wires. 2. 1 remote button and 2 plugin receiver, you can install the receiver in two different places. 3. Including 32 melodies, you can enjoy melodies whenever someone rings at your door. 4. With LED light flashing when the doorbell ringing, remind the elder who can't hear and hearing-impaired to know that the doorbell is ringing. 5. Press the select tone button in the receiver to change the ringtone. Specifications: Condition: 100% Brand New Remote Battery: 23A 12V (Included) Receiver Battery: 2 * 1.5V (Not Included) Receiver Size: Approx. 95*61*26mm/3.7*2.4*1in Remote Button Size: Approx. 72*40*16mm/2.8*1.6*0.6in Weight: Approx.179g/6.31oz To install the battery, you can use a slotted screwdriver to pry open the back cover. With double-sided adhesive, it can be directly glued to the security door. The back cover is reserved with screw holes, which can be fixed on the wall Package List: 1 * Remote Button (Battery Included) 2 * Receiver (Battery Not Included)