Max-Blast plugs allow you to load them into the borehole as suits your needs. You can push the plug right up to the explosive or leave space for an Air Deck.
Since these plugs are a "Friction Fit" design they are snug in the borehole. This is very useful when you are loading horizontal holes or upholes.
When you are using expanding type explosives you can set the top depth very easily. Just push the Max-Blast Plug down to the desired depth and let the expanding explosive rise up to it. The Max-Blast Plug will remain as set.