NEDIS SMART WIRELESS USB DOOR CHIME SmartLife WI-FI Door Chime USB 5V DC, Expand your Nedis Smart Video Doorbell with this Wireless Door Chime, Always know Someone is at your Door even if you don’t have, Your Smartphone within Reach or if it is Switched Off, You only need to Plug it in a USB Port &, Select the Melody & Volume with the SmartLife App, Connects Wirelessly with the Doorbell for Maximum Flexibility, Compatible with the Nedis Smart Video Doorbells, Wireless Connection for Flexible Placement in your Home, Option to Connect up Multiple Chimes to a Single Video Doorbell, Melody and Volume Adjustment Via the SmartLife Application