Desiccant breathers are multi-tiered devices installed on your machines to prevent the entry of two crucial contaminants: moisture and particles. Equipment like gearboxes, pumps and reservoirs must "breathe" when the air in the headspace expands and contracts due to temperature changes and oil level changes. In the case of hydraulic systems, incoming fluid displaces air or when hydraulic components are working. Each time equipment "breathes," dirt, debris and moisture are brought in, contaminating the lubricant and damaging the equipment over time. Since we know at least half of lubricant contamination comes from outside machinery and most machines are designed to "breathe," it's a good idea to stop these contaminants at the source. Enter desiccant breathers.