Keep Pool Cover Flat: This water tubes could weight pool cover tightly to keep pool cover flat to prevent wind messing the pool cover, which helps keep you pool clean during winter. Great Airtightness: The PVC material prevents everything and the sealed edge make sure airtightness of inground pool water bag, so that you can fill water or sand in the pool cover water tube to weight pool cover. Excellent Quality: Our swimming pool water tube is made of thickened PVC material, against tear, wear and extreme weather well, which is the perfect and economical winter pool closing What You Will Receive: This package includes 8 pack pool cover water tubes, each sizing , which is great for weignt the pool cover. Easy to Fill: We designed a mouth on the pool cover water tubes, convenient to fill water or sand, besides, the cap of pool water bag prevents water leakage. It is super easy to operate. size: 29 x 30cm Material: pvc colour: blue Package Contents: 8 x Wall Bags Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.