Description This item is a violin bow straightener, made of premium ABS and steel materials, it is durable and use. It is used to correct the wrong playing posture to develop a good bowing habit for beginner. it adopts double section double track design , it is more stable and convenient . Features - Color: Black- Material: ABS and steel- Size: about 15.3x12.5x1.3cm/6.02x4.92x0.51inch- It is more convenient for beginners to practice.- ABS and steel materials for durable use.- Users can insert the steel bar into the corresponding jack according to their own requirements - Lightweight for portable carry.- This straight straight orthosis is easy to use and has a remarkable effect, allowing the practitioner to pay more attention to the rhythm and intonation Packing list: 1 x Posture Corrector