Anderson Manufacturing Co Inc, Winter Duck Plug (fits 1-1/2" Threads), Color: White/Yellow, Size: 1.50"
Allows plumbing lines to be winterized without draining the pool. The patent-pending "duck-bill" valve allows a large flow of air and water to be blown from the return plumbing but does not allow water back into the lines.
Perfect for those who have a vacuum port far under the waterline.
1.5" thread fits most pool fittings.