This Dunlop 218 glass slide provides a warm, thick tone that accentuates the middle harmonics of your sound, featuring heavy wall thickness and a medium diameter. Dunlop Glass Slides offer a warmer, thicker tone accentuating the middle harmonics of your sound. Processed from high quality boron silicate. Heat-treated and annealed for a flawless tube. 20 x 29 x 51mm / .79 x 1.14 x 2.00". Fits ring sizes 10-11.