49 Brilliant Garage Organization Tips, Ideas and DIY Projects - Page 31 of 49 - DIY Crafts. This looks like Bouillon Cube jar lids screwed to the board, so jar part can screw onto the lid. I've also seen done with baby food jars.
Available for free or cheap at all home improvement stores, PVC pipe is totally great for home storage and organization in different ways. Take a look at these DIY PVC pipe storage ideas for inspiration.