This black borosilicate tubing is sold by the piece, 20lb case, and 50lb case. The tubing is four foot in length with an approximate outer diameter of 9mm. The black is saturated and virtually opaque. When blown thin, it becomes transparent. Each piece of tubing weighs approximately .2lbs. A 20lb case comes with about 100 pieces, and a 50lb case comes with about 250 pieces.
