Features: The arrows spinner tester roller design, which rotates smoothly, have low resistance and accurate measurement. The arrows spinner base adopts magnetic suction design, with excellent craftsmanship and flexible use and placement. Make of alloys, strong and enduring, not easy to wear, and can simply and clearly observe the straightness. Simple operate: Place the arrows on the detectors, and move the arrows with good straightness by hand. The arrows spinner can used for a variety of arrows shafts of different thicknesses, and bracket can also support a variety of angles to measure arrows shafts of multiple size. Specifications: Component: alloys Size: about 25.5x6.5x4.50cm/10.04x2.56x1.77inch Package Includes: 1Pc arrows Straightness detectors note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.