I have worked in the industrial construction piping trades for 43 years. I started out as a pipefitter and welder and worked my way into management and engineering. Through the years I spent a lot of time laying out saddles, laterals, miters dummy legs, etc. I had to lay them out calculating all of my ordinate lines on the pipe. I created this template layout book to save any individual a lot of time of calculating the lines. You can make a template from the book or lay it out directly on the pipe. the dimensions are there for you. Note: If you make a template from the dimensions in this book