The 10Y29 is built with you and your home in mind. It is designed to be less of an eye-sore in rooms being only 104 mm wide and 40mm deep. It also has a reduced sound test facility.
The Kidde 10Y29 Optical Smoke Detector has a 10 year sealed lithium battery.
It has a large push to test button, which makes weekly testing easier.
In most alarms, when you press the test button it releases its 85Db siren, which is not always ideal when you are standing there pressing the button. Whereas the 10Y29 is designed to release a quieter test button activation alarm.
The 10Y29 has a Tamper proof high performance FDK (Fuji) Lithium battery Soldered on PCB. The battery specification is critical to long term performance.