New tool invented by carpenter in the video,made for cutting-framing in roof plywood but can be used for much more buy it here https://www.amazon.com/V-Line-Clamp-Measure-Chalk-Holder/dp/B008L1F4II a real carpenter with 30 years experience, check out other videos as well great for do it yourself,Makes Framing homes and cutting in roofs faster and easier
