Dimension: knife size: length: 8.76 inch, blade length: 4.13 inch, blade thickness: 4.72 inch, blade thickness: 0.05 inch. Comb size: length: 8.66 inch, blade length: 3.94 inch, shank length: v, blade thickness: 0.05 inch. Hardness: hrc52. Surface treatment: silver titanium. Trainer knife has a comb blade with weight reducing cut-outs. The blade is not sharp and it cannot be sharpened due to the design. Knife handles feature pin and channel contracture and look extra thick. But they are designed to reduce weight. So they are not too much heavy, have a good feel in the hand, and won't slip. The butterfly knife without a blade. It is 100% legal in the us and, unlike a real knife, you can't cut yourself. The butterfly trainer will help you learn how to flip without getting injured but, note, you can develop bad habits if you stay on the trainer too long. For example, you can ingrain some poor flips that, with a trainer, won't hurt but, with a real balisong, will hurt a lot. I recommend you to train with a trainer until you feel confident enough to move onto the real thing-no more, no less. If you don'' own a butterfly knife yet or if you are wondering if flipping is for you, get a trainer and try it out. Package include: 1x butterfly knife trainer.