ST-99

——ST-99B——
- Wired Electronic DC door chime
- 12 pcs melodies recycle or only ding-dong sound
- Power by 2pcs AA/LR6 battery

——ST-99D——
- Wired Electronic AC door chime
- 12 pcs melodies recycle or only ding-dong sound
- Power by 220V-240V AC

——ST-99T——
- Wired Electronic AC door chime with build-in transformer
- 12 pcs melodies recycle or only ding-dong sound
- Power by 220V-240V AC,internal 8V operation