Safety Harness and Life Lines?

[Wrangler95]

I have safety harness and lifelines that are probably 10 years old.They have never had a load on them and look great but thinking about buying new harness and lifelines because of their age.If I buy new ones how would I know how long ago they were manufactured,don't want to buy some that were made years ago.I checked at Walmart yesterday and they had safety lines but no year of manufacture.

 

[Remington700]

I just bought some and it came with a card that said they are good for 5 years. It said your time starts from when you buy it and send the card in.