Luyben 318506 L2215 Bb Clarinet Ligature Black Incorporates thumb screws with contoured heads, providing a sensitive, comfortable feel for reed adjustments Made of a plastic material which gives it many of the characteristics of string, allowing full vibration throughout the reed Will not distort or crush reed fibers nor warp mouthpiece as do metal ligatures Top and bottom straps are spaced wider apart and work independently of each other (helps regulate and control reed opening) Sound posts are scientifically designed to give equal pressure and full reed vibration (notice holes in center of sound posts)