Dunlop 235 Tempered Flare Slide, Large Accentuate the middle harmonics of your sound with this pyrex glass slide, processed from high-quality Boron Silicate Dunlop 235 Pyrex Glass Slides have a warmer, thicker tone accentuating the middle harmonics of your sound One of today's most popular slides, it's processed from high-quality Boron Silicate which is heat-treated and annealed to produce a flawless tube 7/8" inside diameter x 1-1/4" outside diameter x 2-3/4" length Dunlop 235 Pyrex Glass Slides have a warmer, thicker tone accentuating the middle harmonics of your sound