Spun-polypropylene filters are disposable filters and cannot be cleaned and used more than once. However, you can filter multiple kegs with one filter. 5-10 micron is considered rough filtration, 3 micron will remove most yeast, 1 micron filtration will remove almost all yeast, and .5 micron is nearing sterile filtration. All filters are rated nominal (will filter out 80-85% of matter at given rating) except for .5 micron absolute which will filter out 100% of the material at .5 micron.
All prices are in USD.