Why CW8100 flux pen doesn't come with expiry details printed?

Why CW8100 flux pen doesn’t come with expiry details printed?

I spoke with our product manager and there should be a printed date on the pen which. You can then use the datasheet to check the shelf life of the pen.

According to the datasheet https://www.chemtronics.com/content/msds/TDS_CW8000.pdf the shelf life for the CW8100 is 5 years.