Features: Adjustable width bow straightener can effectively solve the problem of bow straightening in violin performances and improve performances quality. Made from ABS and steel materials, durable and comfortable. Simple and easy to use, convenient to carry. Adopting a double track design, the grooves plastic clip installation is more stable and convenient. It can help the performer maintain correct arches, improve playing skills and expressiveness. This straight bow corrector is easy to use and has a remarkable effect, allowing practitioners to pay more attention to rhythm/pitch. Specifications: Material: ABS and steel Size: As shown in the picture Package Includes: 1x Violin Bow Straighten Collimator note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.