Like almost every other household utility item, the humble doorbell has added a lot of modifications to its fundamental design. We all remember the heavy, vintage-styled door knockers that would announce the arrival of a guest. And although it fulfilled its duty well, it was soon replaced by the more efficient, electrical ding-dong bells as they were claimed to be more audible. The latest in the market are the wireless doorbells. They are preferred over their wired counterparts and there several reasons to explain it.