Demand the original Mister B ! Here is the official cylinder Mister B, for a "pro" quality.
The Mister B cylinders have a much better valve closure seal than conventional models.
Advice from the pros: if your cylinder lacks opacity, shave and use some lubricant!
Dimensions of the cylinder: 5.7 cm in diameter and 25 cm in length (inner length 23 cm).
Can only be used with the pressure control pump Mister B sold separately.