The Jackson Safety Jumbo Contour Marker (#4) is a timesaving tool used to lay out pipe and structural steel joints. Laterals at any angle, tees, wyes, crosses, elbows - any type or size of joint can be quickly and precisely laid out. No more complicated mathematical formulas, no more cut and try, and no more needless material waste. The Jumbo Contour Marker can be used to lay out pipe from 8 to 48 inches in diameter or structural steel members up to 18 inches. It consists of an X-shaped frame, calibrated protractor, and a triple-jointed marking arm and holder. The holder accepts a soapstone crayon and comes with a durable web strap to hold the unit in place, and a built-in dial bubble to find an accurate center location. The frame folds into a compact tool that fits into a pocket or tool kit, and it can be used upside down or right side up. The protractor is calibrated on both side - on in degrees and one in rise-inches per foot.