(CNN)- Almost 500-thousand smoke alarms that might fail are being recalled.
Safety device brand Kidde says it sold about 450,000 of the alarms in the United States and 40,000 more in Canada.
The affected units are model numbers P-I-20-10 and P-I-90-10 with manufacture dates between September of 2016 and October of 2017.
They were sold through retailers including Wal-Mart, Amazon and Home Depot as well as from Kidde’s website.
Kidde advises customers to remove their fire alarms from walls or ceilings and look through the opening on the side for a yellow cap.
This cap can prevent smoke from reaching sensors and activating the alarm.
Customers that see yellow caps should contact the company for a replacement unit.
If no cap is present, the alarm can be safely re-installed.