Below are Amazon links to third party knife blades (with housings). I strongly advise against buying them. If you read the reviews, you'll get why.

https://www.amazon.com/Housing-Cricut-Accessories-Set-Perfect-Chipboard/dp/B0BGS914Z1/ref=sr_1_6?crid=XCUE8BQ6M3EF&keywords=cricut%2Bknife%2Bblade&qid=1674455101&sprefix=cricut%2Bknife%2Bblade%2Caps%2C178&sr=8-6&th=1

https://www.amazon.com/Housing-Cricut-Accessories-Set-Perfect-Chipboard/dp/B0BGS914Z1/ref=sr_1_6?crid=XCUE8BQ6M3EF&keywords=cricut%2Bknife%2Bblade&qid=1674455101&sprefix=cricut%2Bknife%2Bblade%2Caps%2C178&sr=8-6&th=1

https://www.amazon.com/Housing-Cricut-Accessories-Set-Perfect-Chipboard/dp/B0BGS914Z1/ref=sr_1_6?crid=XCUE8BQ6M3EF&keywords=cricut%2Bknife%2Bblade&qid=1674455101&sprefix=cricut%2Bknife%2Bblade%2Caps%2C178&sr=8-6&th=1

https://www.amazon.com/Knife-Blade-Drive-Housing-Cricut/dp/B082XSTRHC/ref=sr_1_8?crid=XCUE8BQ6M3EF&keywords=cricut+knife+blade&qid=1674455262&sprefix=cricut+knife+blade%2Caps%2C178&sr=8-8