This puzzle is very similar in structure to Oskar's proportional oh cube except this uses curved cuts and ads an extra twist to make it much more challenging. Turning is decent and gets better over time, but you have to make sure the puzzle is lined up well otherwise it will tend to catch. This was also designed so that the pieces can be enterchangeable with the pieces of the rhombic raptor.
other products needed for assembly are:
for the 4 square corners: http://www.amazon.com/Machine-Plated-Phillips-M3-0-5-Threaded/dp/B00F32DUSY/ref=sr_1_2?srs=3041233011&ie=UTF8&qid=1453215607&sr=8-2&keywords=m3+jis
for the 8 triangle coreners: http://www.amazon.com/Machine-Plated-Phillips-M3-0-5-Threaded/dp/B00F32DMQY/ref=sr_1_4?srs=3041233011&ie=UTF8&qid=1453215607&sr=8-4&keywords=m3+jis
stickers: send the sticker design found here: https://www.dropbox.com/s/r19rr7sigasbvln/raptor%20jewel%20pillowed.DXF?dl=0 and the stickers shown in pics were ordered from http://oliverstickers.com/unique-design-stickers.html you just have to place the order, then email him the drawing file. For stickering the puzzle, it helps a lot to make sure it's clean, clear of all loos debris (small vac helps with that) and then to use a hair drier to help the sticker to stick to the 3d printed material better.