This a 3D Printed Bowling Ball Quarter Scale. This is used to place layouts on bowling balls. This 3D model was created and printed by me. (Made and Shipped in the USA)
It has the Inch marks on the front with 1/8" 1/4" and 1/2" marks.
The back arch has degree markings on it, center back is 0 and to both sides up to 90 degree. Markers are in 1 degree and 10 degree increments.
Please contact me if you have any questions.