H&Y Tech Wireless Doorbell Operating at over 900-feet Range in open air with Over 50 Chimes, No Batteries Required for Receiver,White, Fixed Code Our Original Classic H&Y B doorbell. A stylish modern design in classic white! This is a B Series doorbell. Operating range of over 500 feet. (900 feet in open area). Remote transmitter button is rated IP44 weatherproof and acceptable for outdoor use. Over 50+ different ring tones. Four levels of adjustable volume from 30db to 110db. Easily plug receiver into an electrical outlet (no batteries required for main receiver). CE, FCC, RoHS certified. Includes 1 plugin receiver unit and 1 remote transmitter button, double sided sticker, anchors, screws, and battery for remote transmitter. (This unit is a fixed code B Series doorbell)