1 micron absolute filter the only choice if you absolutely need 1 micron filtration
Most standard micron filters are known as nominal
this means that most of the filter around 85% as rated at the advertised micron level.
An absolute filter is as the name suggests an absolute filter, 100% of the filter is at the advertised micron level.
Height 20 inch
Diameter 4.5 inch
Micron rating 1 micron absolute