Typical efficiencies of 99% removal of all oil droplets between 3 and 10 microns are achievable, coupled to a low pressure drop of often less than 5 millibar.
 
Knitted wire mesh breather materials
Breather elements are normally manufactured from high quality galvanized steel, stainless steel. It enhances corrosion and temperature resistance.

Knitted mesh breathers and filters are designed for operating environments where other media fail. Made fromwire types chosen specifically for their resistance to hostile agents such as temperature extremes and corrosives, these compressed mesh elements can be tailored to meet a wide range of filtration or flow targets.
Features & Benefits
Highly efficient moisture removal with low or negligible pressure drop.
Available die-compressed, layered or spiral wound to accommodate any size or cavity shape.
Will operate effectively over a wide temperature range depending on material choice.
Density and surface area easily varied to suit efficiency requirements.
Easy installation into housings or engine cavities.