Steel construction for durability and long lasting performance Dual-Track Design: A two stage dual track with twin bushings lets you easily insert the steel rod into the corresponding carriages to suit your needs. The grooved plastic card labels are stable and easy to install Improve beginner practice: An effective instrument accessory that helps beginners focus on rhythm and intonation, improving overall learning experience Specifically designed for bow clamps: Tailored for bow clamps, this correction accessory provides the support and guidance needed to improve practice and technique Use scenarios - In daily practice for beginners to build consistent bowing rhythm and pitch accuracy during scales and long tones - In studio or classroom with an instructor to guide bowing dynamics and intonation during exercises - In a home warm-up routine to establish a standard bow path and reinforce muscle memory for better technique