If you own one of these systems and want to add another ringer this does the job. You do need to pair it with you doorbell units.
Optimize Viewing With CAVN Black Angle Mount For Ring Video Doorbell 1 2 3 4 - Adjustable 30 To 55 Degree Angle
30 Review
AVANTEK D-3W Waterproof Wireless Doorbell Kit With 2 Plug-In Receivers Operating At Over 1300 Feet, 52 CD Quality Melodies, LED Flash, And Long Range
34 Review
Wireless Doorbell Chime - AVANTEK Mini Waterproof, 1000 Feet Range, 52 Melodies & 5 Volume Levels With LED Flash
31 Review
๐ Adjustable Anti-Theft Video Doorbell Mount Bracket - No Drilling, Unobstructed Doorbell Motion Sensor - Ideal Mounting Accessories for Homes, Apartments, and Offices
31 Review
โก๏ธ Sunpark LC-12014T (1) FC12T9 32W Circline (1) 2D 38W (1) FC16T9 40W Circline (1) FC9T9 30W Circline Lamp Compact Electronic Fluorescent Ballast with Circline Lamp Plug 120V
7 Review
๐ก Electronic FL Ballast ICN-4P32-N (Formerly ICN-4P32-SC) for 3-4 F32T8 F40T8 F17T8 Lamps, 120V/277V Compatibility
5 Review
Wireless Electronic Ballast Interface Certified
8 Review
Fulham WorkHorse WH2-120-C Adaptable Ballast - 2 Pack
3 Review