Pros : Following the instructions for the round or square knob molds these work perfectly. Screws fit tightly.
Cons : No instructions, tips, or tricks shipped with the item itself. I had to use the knob project sheet to get any info and hope these matched what was mentioned.
Other Thoughts : I tried using E6000 with these and that was still too loosy goosy, I had to switch to a resin epoxy to glue them in, and that was messy... not to mention hard to keep them centered just right, but if you put in the screws to hold the barrels in place, be very careful to keep the threads 100% clear & clean since I lost one to a thread of epoxy drifting into the wrong spot.