The simple way to practise straight bowing This product is a violin bow straightener, made of high- quality steel wire material, durable and easy to use. It is used to correct the wrong playing posture, so as to develop a good bowing habit for beginners. It adopts double- section and double- track design, which is more stable and convenient. Size for : 1/4 1/8 Violin use Self bowing practice guide, it can help you develop correct bowing and wrist movements. It is more convenient to practice for beginners. Fine workmanship. and portable. This kind of upright orthosis is easy to use and effective, so that practitioners can pay more attention to rhythm and intonation. Colour:black Material:rubber Package Contents: 1 x Violin Bow Collimator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.