The Rovner Dark offers the free-blowing performance of a string ligature with the convenience of a standard screw ligature. Rubberized polyester fabric and machined brass hardware. Rovner Ligatures Rovner Ligatures also greatly improve reed playability. Reeds that are totally unplayable on other ligatures will often perform well with the Rovner. The ability of the Rovner Ligature to extend reed life is unparalleled. More rigid ligatures actually hammer the cane fibers during vibration, eventually destroying the reed's tonal vibrancy. Not so with Rovner; most players find their reeds will play until the tips finally succumb to fatigue and fall apart!Selecting A Rovner Ligature Due to the design of the Rovner ligatures, they fit a wide range of mouthpieces. The above descriptions are general but are accurate for MOST mouthpieces. For more exact information regarding sizing, please follow the MORE INFO link above to read the sizing chart designed by Phil Rovner.