My current doorbell at home has lasted me for 28 years (since 1985) and hence I got a new SoundTeoh No. 77 Wireless Doorbell from Funan’s Challenger for S$28.60 (member’s price: S$25.74).
28 years later, it seems technology also changes doorbell. There are so many types right now: wireless, wired, AC powered, battery powered, mp3 (using SD card) and 20 built-in tones.
I chose the wireless 3xAA battery powered doordell that comes with 20 built-in tones.
I love the portability of the wireless battery powered because you can place the receiver anywhere in the house as compared to the AC wireless powered one which depends on an electrical outlet.
I recommend placing the receiver in the middle of your house so that the sound can be heard somewhat evenly from all corners in your house. Since the receiver is small, you do not need to mount it on a wall, you can just place it on a table or behind some isolated corners that you will never notice.
The sound is loud at maximum level so I have to adjust it one level lower so that it is not deafening to the ears!