RAH, My pond has the UD slide gate valve. It is made of plastic about the thickness of a cutting board functioning as the open/close feature. Other than that there are 6 or 8 stainless bolts/springs/nuts (no need to worry about rusting shut) to set the amount of pressure required to open/close the valve. My drain is 3-4 feet off the bottom of the pond with about a 10x10 sump area for collecting debris. I�m wanting to cage the area around the drain to allow leaves and such to pass through but not fish. Do you believe the 1� holes will suffice? Thanks, Heppy
