The Dunlop 202 Pyrex Glass Slide is clear, shatter-resistant guitar slide that can take the heat. Choose a Dunlop Pyrex Glass Slide for a warmer, thicker tone accentuating the middle harmonics of your sound. The Dunlop 202 Pyrex is today’s most popular guitar slide. Processed from high-quality boron silicate. Heat-treated and annealed to produce a flawless tube. 3/4″ inside diameter x 4/5″ outside diameter x 2-3/4″ length.