Kidde is recalling nearly 500,000 smoke detectors that were sold in Canada and the Unites States over concerns they might not be able to detect smoke.

The North Carolina-based company says 40,000 of the affected products were sold in Canada between November 1, 2016 and January 25, 2018.

The recall includes two versions of Kidde dual-sensor smoke alarms with model codes PI2010CA and PI9010CA.

Health Canada says the product has a yellow cap that can cover one of the two smoke sensors, which compromises the smoke alarms’ ability to detect smoke.

The agency has provided the following instructions to identify the presence of the yellow sensor cap:

1. Consumers should remove the alarm from the wall/ceiling and visually inspect.
2. Consumers should check the brand name and look for the unique design of the PI2010CA and PI9010CA smoke alarm.
3. Consumers should then locate the locking tab on the back of the alarm, turn the alarm on its side and look at the opening closest to the locking tab.
4. If a yellow cap can be seen in the opening the unit is affected and must be replaced. Consumers should not attempt to take apart the alarm, open the casing, or otherwise remove the yellow cap themselves.
5. If no yellow cap is present, consumers should reinstall the smoke alarm and no further action is needed.

There have been no reported injuries associated with the product in Canada or the United States. The company says they have received one report from a consumer who identified the yellow cap before installing the alarm.

Anyone who has the affected product can contact Kidde to request a free replacement smoke alarm.