タイトルまたは説明

These are made from sheets of vinyl.  The vinyl is slit and then sealed on all four ends.  They are generally 2 wide and may be 8 or *0 in length.  They may be made from *0 mil, *5 mil, *0 mil or even *0 mil. made of PVC, in usual, the color is blue or black.

There is a vinyl fill valve inserted in each bag to allow them to be filled with a garden hose. 
 

Once these water bags are filled, they are placed along the edge of the winter cover on in-ground pools to hold the cover in place, the peak season is from Sep to Mar.