The P-3 from Everhot is a 1/2” Copper Cap. It's used to terminate the end of a copper pipe. 

Features:

• Wrot Copper Fittings;
• ASTM B75;
• Alloy C12200;
• NSF Certified;
• UPC Listed;

Cross reference:
 

• Elkhart: 117;
• Cello: WP17;
• Mueller:WC-415;
• NIBCO: 617;