Made from glass, processed from wine bottles. Handmade slide bars, bottle necks. How about a set of 3? Sizes: Thin inner diameter φ18.5mm Thick inner diameter φ22.0mm (slightly different in length) Total lengths: 66.8mm, 70.0mm, and 73.2mm, all conical. *Please allow for slight measurement errors. In my opinion, compared to commercially available glass slide bars, wine bottles have more thickness and weight, allowing for longer vibrato and a beautiful sound. The deep green color also adds to the atmosphere! Handmade. There may be some minor chips, but they do not affect playing. R-shaped processing with files and sandpaper. No claims and no returns. Thank you for looking.