Fangrui Product Details Comprehensive Set: Receive 16 Round Pool Cover Weights, Each Measuring 13.5x9 Inches. Equipped With Robust Hooks, These Weights Are For Securing Pool Covers On Pool Sizes, Ensuring Stability And Reliability Throughout The Seasons. Effective Pool Protection: Utilize These Heavy-duty Weights To Keep Your Pool Cover In Place, Preventing It From Being Displaced By Strong Winds Or Harsh Weather. This Not Only Keeps Your Pool Clean And Free From Debris But Also Significantly Cuts Down On Maintenance Costs. Material: Constructed From High-density, Cold- Pvc, These Weights Are Designed For Year-round Use. They Remain Functional Even At Temperatures As Low As -10f (-23c). Note: Fill The Bags To Three-quarters To Allow For Water Expansion And Prevent Bursting. Enhanced Seal And Leakproof Design: Our Pool Cover Weights A Thickened Seal Lid And Ring, Ensuring A Tight Lock And Strong Seal During Use. Compatible With Most Garden Hoses, They Are Easy To Fill, Use, And Drain, Providing A Hassle-free