Wilkins RK34-375V | Complete Pressure Vessel Repair Kit, 1/2"-3/4 InchesThe Wilkins RK34 375V is a complete pressure vessel repair kit compatible with 1 2 and 3 4 Inches Model 375 and 375XL Reduced Pressure Principle Backflow Preventers , designed to speed up repairs while lowering maintenance costs and extending product life . Key Specifications: Compatible Sizes: 1 2 and 3 4 Inches Compatible Models: 375 and 375XL Notable Certifications: NSF ANSI 61, ASSE 1013 NOTICE: Do not use with water that is unsafe or of unknown