UHPPOTE 12VDC Wired Doorbell Chime For Access Control System Volume of doorbell: 90db Switch is not included Working Voltage: DC12V Wired Doorbell for access control system Need work with access system with signal port Wired door bell 12VDC 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)x2-1/2(H)x1(D)in / - Approx. 88(W)x62(H)x24(D)mm Material: Plastic Color: White Wired Doorbell special for access control system &#034;Ding-Dong&#034; Voice output without built-in battery Please search &#034;ASIN: B00VBRURXG&#034; for get complete system 1 x Wired Door Bell for Access Control 1 x English manual Red: V+ Black: V- Yellow &amp; Orange: Signal