HWMATE DC12V Wired Melody Doorbell Door Bell Chime for Home Office Access Control System Dingdong Musical

Feature:
12V Wired Doorbell Chime For Home Office Access Control System
Working Voltage: DC12V
Material: Plastic
"Ding-Dong" Voice output without built-in battery, Connect to DC 12V Power Directly
Switch is not included

Specifications:
Wired door bell 12V for security access control
Features a bell sound, small size and wall-mount hole, very easy to install
Switch is not included; Volume of doorbell: 90db
Working Voltage: DC12V
Dimension: - Approx. 3-1/2(W) x 2-1/2(H) x 1(D) in
Material: Plastic
Color: White
"Ding-Dong" Voice output without built-in battery, Connect to DC 12V Power Directly

Instructions:
1 Connected to DC12V power supply, then the red positive (+), then the black negative (-)
2 Green, yellow, two-line short answer it, it can send two ding-dong ding-dong sound, it's connect to the switch.

Package:
1 x Wired Door Bell