Similar to the Ventguard™ Breather, the Hydroguard Disposable comes with check valves to ensure no excess pressure or vacuum builds and a clear polycarbonate casing for viewing the desiccant as it changes color.  They Hydroguard series come with an expansion chamber to isolate lubricants from all levels of ambient humidity. 

Hybrid Breathers:

Gearboxed and Other Low-Flow Applications
High-Humidity Applications
Intermittent Applications (or infrequent cycles applications)
Limited Wash-Down Applications