UNDATED – Almost 500-thousand Kidde brand smoke alarms that might fail are being recalled.

About 450,000 of the alarms were sold in the United States through retailers including Wal-Mart, Amazon and Home Depot as well as from Kidde’s website.

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.

Kidde advises customers to remove their fire alarms and look through the opening on the side for a yellow cap.

This cap can prevent smoke from reaching sensors and activating the alarm.

If no cap is present, the alarm can be safely re-installed.

Customers that see yellow caps should contact the company for a replacement unit.

For more information from the Consumer Product Safety Commission  here.