Experts suggest properly testing your detector when first installed, and then once a year.
Pushing the test button on the carbon monoxide detector only checks the alarm and electronics, NOT the Gas Sensor.
This kit contains a hermetically sealed glass tube of pure carbon monoxide (CO). When the tube is broken inside a sealed plastic bag containing the detector, it produces about 400ppm of CO and air mixture. This will set off the alarm if it is working properly.
INSIDE THE BOX
1 Hermetically sealed glass tube of pure carbon monoxide
1 Plastic bag
1 Twist tie
Package Dimensions: 15.2cm x 11.4cm x 1.0cm (6.0in x 4.5in x 0.4in)