ALVIN Master-Bow 6-Inch Combination Compass with Beam Bar
Create circles up to 20" in diameter. 6" compass includes a beam bar that can be attached to one of the legs, allowing for larger circles. Features a fiberglass ring head and pivot design for smooth, firm adjustment. Built-in spindle stop prevents over-extension. Made from zinc. Comes in a durable hard plastic case with two additional leads.