The HorACE BG-140 bow guide is made of transparent plastic and supports string instrument playing. It's for practicing bowing, especially for beginners and children just starting out, for those who have developed bad habits in their bow direction. Some teachers may have mixed opinions, but I think it's fine to use it for a certain period. Please consult with your teacher if you have any concerns. It has been used very little, but the box has aged. I will discount the price if you don't need the box. Shipping included. - Brand: HorACE - Model: BG-140 - Type: Bow Guide - Material: Plastic - Color: Transparent Thank you for looking. #Violin #Violin #Bowing #Bowing #Orchestra #MusicCollege #Music