Size 8-3/8" X 10-3/8" X 20 mil. This transparent plastic tool has tiny holes to precisely locate your pen or pencil. It makes layout of geometric templates and patterns quick and easy. YOU can precisely draw: DIAMONDS - From 1-1/2 to 10 inches long (for 5, 6, 8, & 12 point stars). TRIANGLES - From 3/4 to 5 inches long in 4 common shapes. CIRCLES - To 20 inches diameter by using the holes as a compass. CIRCLE SEGMENTS - From 8 to 36 segments per circle are clearly marked on a 10 inch protractor.