The Dogal Blu Tag - Concert strings are the result of painstaking research done by our technicians with the collaboration of professional concert artists, aimed towards the creation of the "PERFECT STRING". These strings are fully qualified to satisfy every requirement and can be fitted onto any instruments, modern or antique, without risking unpleasant side-effects caused by improper stringing. The characteristics of the Dogal Blu Tag - Concert strings are the use of highest-quality materials and non-assembly line winding of each string with tolerances down to 1/100th of a millimeter during production, and perfect fifths plus softness to the touch coupled to sweet yet powerful sound when played.Flat wound. Round Core.