This is a segmented plywood pen and an acrylic pen with standard kits from PenKitsMall. The one on the right is an European kit and the left is a comfort style. The european kits make beautiful pens but it takes a little more skill. You have to cut a tenon into the top blank for the center ring to sit in. If that tenon is too big the ring wont fit and if it\'s too small (even by 1-2mm) the center ring will float around on the pen. It\'s best to test multiple times. I use a parting tool to cut that tenon and it seems to work well. Just remember to cut it a \"little\" large because it will thin out some on your finishing/sanding pass. The segmented ply always comes out nice...for the first one, then they get kind of boring. HOWEVER, PenKitsMall is now selling some diagonal cut segmented ply that finishes up a lot more interesting than the standard straight cut. Take a few minutes to check out their blanks section. Even with the shipping costs you\'ll save some cash if you and a couple buddies order together.