Hydroponic Kratky Jar Covers

This is a cover to block light and turn a 32oz mason jar into a hydroponic planter. It is used to grow plants using the kratky growing method. It fits wide mouth 32oz jars with maximum diameter of 4 inches. I have three different designs but they all use the same lid. Works with a 3 inch net pot. The ones in the photo are sloppy due to a problem with my extruder that has since been resolved.