A great tool to learn Violin, the fret markers replace the tapes on the fingerboard method of teaching fingerings to beginning string students. Great for the classroom teacher or private studio teacher, suit for violin 4/4 students or beginners or kids. High Quality, water proof,oil proof, with glue,Removable, not leave glue when peel off. Easy to use: No need to loosen or remove the strings to put it on. This violin fingerboard guide stiocker decal have helped thousounds people to learn violin. It is one-picece back sticker, waterproof, oilproof,with glue,can stick very well and not leave glue when peel off. Very to use,JUST PEEL IT OFF, PUT IT ON, AND PLAY Fret finger guide sticker for violin 4/4. Colour:Black Material:Pressure-sensitive adhesive Package Contents: 1 x Finger Guide Sticker Only the above package content, other products are not included. Note: Light 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.