Perfect Replacement: Our Mechanical Wired Doorbell Can Be Used In Conjunction With Most Doorbell Switches, It Is Very Suitable To Replace Your Old Doorbell.Easy To Install: The Doorbell Is Screwed In, Install And Use Without Complicated Tools, Saving Money Time And Effort, The Product Is Small And Does Not Occupy Space. Can Be Cleaned With A Dry Towel.Ac Powered: The Household Wired Doorbell Is Powered By Ac Power. After Installation, You Don'T Need To Replace The Battery Or Charge It. It Is Once And For All, Easy To Use And Convenient.High Quality: Ding Dong Home Doorbell Adopts High Quality Abs Flame Retardant Shell, Resistance To Oxidation, Impact And Corrosion, Durable Appearance , Simple And Elegant.High Power Speaker: This High-Quality Wired Doorbell Uses High-Power Speakers, With Loud Sound And Strong Penetration, Which Can Penetrate Any Room To Remind You And Others. To Your Family That The Practicability Is Very Good.