Bubble glass and straight glass
The profile of a tank’s glass changes where it sits against the tank body. For a protective sleeve, the important measurement is the widest outside point of the glass actually fitted.
Look at the widest point
Bubble glass bulges beyond its ends. Straight glass has a more even profile. Measuring the metal base alone can miss the widest exposed area, particularly after a change of glass.
Use shape and size together
VapeGuard is primarily intended for exposed bubble glass. Being inside a stated diameter range is a starting point; check that the shape allows the sleeve to sit properly without covering airflow or controls.
Measure again after a change
If you swap capacity or fit a different glass edition, recheck the outside diameter. A familiar model name does not mean the fitted dimensions are unchanged.