Ideal for testing 9K through 24K gold, and platinum Can determine if item is gold plated or solid gold Non-destructive solution, safe for gold and platinum Shelf life of 6 months after opening These replacement chemicals are great for TES-170.00. They help test 9K through 24K gold and platinum. Non-destructive solution won't harm your rings and other gold jewelry. Has a shelf life of 6 months after opening.