These PEX GUY Stainless Steel PEX Cinch/Pinch Rings come in bags of 100 pcs and are used with PEX piping to help hold PEX piping onto fittings. Due to the compactibility of this ring’s design, it is perfect for tight spaces that a crimp tool might not be able to reach. Thanks to the corrosion resistance of stainless steel, these rings are suitable for a variety off applications from domestic water to radiant heating. Applications: Used to hold 1/2″ PEX piping onto 1/2″ PEX fittings, valves, and accessories Suitable for direct burial or behind the wall applications Specifications: High Quality Stainless Steel Rings For use with PEX SDR-9 tubing only Compatible with: PEX-A, PEX-B, and PEX-C NOT Compatible with: Expander Fitting System, Uponor/Wirsbo Expander System Do Not use with PB tube Certifications & Standards PEX GUY piping is NSF certified since 2010SDR 9 sizing standard,Manufactured to ASTM 876/877 standards, CSA 137.5 (Canadian Certification),Warnock Hersey Canada (Canadian Certification)DIN 4726 (European Standard) Perfect for Radiant or Potable Water Application It is perfect to for any sort of residential and commercial radiant or hot and cold water plumbing applications. Can be buried underground, used under sinks, shower fixtures and to replace any other pipping in the house. Versatile Can be used on brass, copper, stainless steel and poly fittings that are SDR9. Compatible with All PEX Will fit and can be used on any type of PEX piping (SDR-9 sizing standard) for use in North America. Viega, Wisbro, Uponor, Watts, ReHau, Efield, Everhot, Zurn, Nibco, Bow, etc