Shubb AX Reversible Slide;A great invention for quickly switching between slide playing and fretted strings.;The plastic ring of the slide fits on your finger, while the upper slide section can be rotated at lightning speed with your thumb, for example. This allows your slide finger to become a fretting finger again!;Includes 4 Delrin inserts for different finger sizes: SMALL = 17.5 mm, ring size 7 MEDIUM = 19 mm, ring size 9 LARGE = 20.6 mm, ring size 11 EXTRA LARGE = 22.2 mm, ring size 13;Inserts available as spare parts, price for 3 pieces;