Bongs with a wall thickness of up to 7mm. These glass bongs are ideal for both indoor and outdoor use, as the high thickness of the glass makes the surface of the bong less fragile. The pronounced glass thickness provides massive stability and counteracts breakage damage to the bong from being set down too hard, bumping into things or falling over.
The Heisenberg 7mm glass bongs come both as beakers as well as cylinder bongs. What they have in common is their voluminous mouthpieces, which are comfortable to use, as well as the reinforced connection area for chillums and bong accessories. Even if in the worst-case scenario the bong should happen to land on it, there is a greater chance that a chillum will break, because its glass is correspondingly thin, than that the 7mm thick glass of your bong will crack or break.
But be careful! Even with a 7mm bong, more stable does not automatically mean unbreakable. Glass is and remains susceptible to breakage. So make sure to avoid hard knocks anyway.