These are a brand-new range of mushroom growing bag that use a G-type Filter. They have been developed by European industry leaders Sac02 and Mycelia.
This type of filter has a moderate gauge (0.5 microns) and so is ideal for species that have a high oxygen demand and short incubation. It effectively allows high gas exchange without causing damage to the substrate or mycelium.
The filter works in a similar way to a HEPA filter. They are composed of hydrophobic, randomly arranged fibres which trap microorganisms due to the design of the filter, the air must pass through a long filtration distance making it the most effective filter available.
These bags have vastly improved performance compared to other surface filter bags. They have higher gas exchange, little to no dry out zone, better strength and visual clarity.