Features: 1.This violin bow straightener adopts imported silicone gripping feet, which is environmentally friendly and wear-resistant, and does not damage the paint surface of the violin 2.According to the three-dimensional fit design of the edge of the violin, the size is standard, firmly grasp, fit the body, the overall line is smooth, refer to the mellow beauty of the violin, possess good coordination, full beauty, and the elastic design can effectively correct the movement posture 3.This violin bow straightness corrector is suitable for 4/4, 4/3, 1/2 violins. Plays an important role in correcting and improving violin playing skills 4.Self bowing practice guide and help you cultivate correct bowing and wrist action. Encourages straight bowing, the best helper for beginners. Great confidence builder for the student violinist or for the seasoned player who wants to improve their bowing action 5.Using thermoplastic elastomer material, possess high strength and elasticity, light and convenient, easy to carry and use. Easy to store in any violin case specification:Item Type: Violin Bow Collimator Material: Environmentally friendly ABS + silicone Applicable Violin s: 4/4, 4/3, 1/2 PackageList:1 x Violin Bow Collimator