Fangrui Product Details Our Customized Reflux Insulation Bag Is Designed Based On The Actual Conditions Of The Pressure Vacuum Breaker And Perfectly Matches The Pressure Vacuum Breaker. Protect Your Pressure Vacuum Circuit Breaker Equipment From Strong Sunlight, Wind, And Snow [ Material Composition Structure ] The Insulation Material For The Backflow Prevention Cover Is Made Of One Layer Of Waterproof Heavy-duty 600d Oxford Cloth, Two Layers Of Cotton Insulation Material, And Two Layers Of Pe Silver Plated Material Made Of Double-layer Stitching. 600d Oxford Cloth Has Waterproof And Snow Proof Properties, While The Reflux Valve Cover Bag Has Insulation And Sunscreen Properties In Summer, And Has Anti Freezing And Warm Protection Properties In Winter. [ Avoid High Maintenance Costs ] Protect Your Return Pipeline System From Freezing, Cracking, And Blowout Caused By Severe Weather Conditions (such As Snow, Rain, Wind, And Sunlight Exposure Heating). Avoid The Expensive Cost Of Replacing Valves And Maintain Them Annually. Colou