This is a Supply Giant straight coupling with sweat sockets on both its ends. The fitting, which has no tube stop, is made of copper and meets all applicable standards. It is designed for use with copper pipe having a nominal diameter of 1-1/2" and an outer diameter of 1-5/8". ⚠ California Proposition 65 Warning: This product is known to the state of California to cause cancer, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.