This is a Spiral Wound Gasket with Outer Ring - also labeled CGR GASKET
Specs from your label:
• Class: 150# / 150LB
• Size: 5"
• Material: 316L stainless steel
• Qty: 5pcs
What is it used for?
To seal pipe flanges and prevent leaks in piping systems.
You place it between two 5" flanges, then bolt the flanges together. It creates a pressure-tight seal for liquids, gas, steam, oil, and chemicals.
The big flanges in the background of your photo are what these gaskets go on.