The artsy, handmade Silca Sound 421 Large Slide is hand blown with a tapered fit. The thickened end adds mass and has a colorful art design. The wall is 2.8mm thick, with an outer diameter of 28.0mm, and an inner diameter of 22.4mm. Length is 2.6". No two slides are exactly the same. The taper varies on each slide, some thicker, others thinner.