Easy to Use - The Channel Beam Bar For Alvin Beam Compass is a functional replacement part that allows the compass to draw circles up to 48 inches in diameter. Precision Design - Spring-loaded thumbwheel on the top of each slide assembly allows for smooth and precise adjustments. Comes complete with interchangeable ruling pen pencil and divider legs. Ideal for Students - Perfectly useful for all levels whether for geometry class drafting architectural design construction or engineering. Conveniently Packaged - Comes in a hard see-through plastic case for portability and easy storage and transport. Premium Quality - Made in Germany each tool is constructed with heavy-duty materials and finish that can resist stains and tarnishing. Ideal for long-lasting use. Proudly Made in Germany