Features: brand new and high quality Adjustable roller track base system - the spin tester is a unique track base system with 2 rollers. for Arrow spinner inspection tool for all archers, ensure a smooth accurate for arrow flight. Crowned ball bearing - the tester roller is equipped with crowned ball bearing. Roller position can be moved left or right to the desired position and then lock, thus it can square fletched arrows. The for arrow spin tester is an for arrow squaring tool for arrow with or without fletching. This crowned ball bearings provide large surface to support the for arrow and to allow smooth operation even under high pressure. Specifications: Material: Aluminum Alloy Color: As The Picture Shows Package Weight: approx.499g Size: approx.31x6.5x6.5cm/12.2x2.5x2.5in Package Includes: 1Pc x for Straightness Detectors note: Please allow 1-2cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!