Rototape
This unique marking device combines a measuring tape and pencil scribe in one pocket size tool. It will mark a radius of any length between 3-1/2 inches to 6 feet. That means circles ranging from 7 inches to over 12 feet in diameter! It's accurate to within + or - 2mm, and eliminates the need for cumbersome trammel beams. Marks straight lines deep in the middle of large panels. Includes Rototape, centering pin, and pencil leads. USA