Wilkins RK212-350 | Repair Kit for 350 Series, 2 1/2 - 3 InchesThe Wilkins RK212 350 is a complete check rubber repair kit designed for 2 1 2 and 3 Inches Zurn Wilkins 350 and 450 series double check backflow preventers. Key Specifications: Size: 2 1 2 3 Inches Compatible Models: 350, 375, 450, 475 series Kit Components: Check seal rings, O rings, lubricant Notable Certifications: Lead free law compliant Application: Double check backflow preventers NOTICE: Do not use with water that is unsafe or of unknown