When looking for filters it is important to understand two terms used to describe the efficiency of a filter. The first term is MERV. MERV stands for Minimum Efficiency Reporting Value. This describes how effective your air filter will perform. It describes how efficient your filter will be in trapping airborne particles. MERV ratings range from 1-16. The higher the MERV rating the fewer dust particles can pass through the filter making it more efficient. The MERV rating is determined by measuring the varying sizes of dust particles both upstream and downstream of the air-cleaning filter as air is forced through the filter. These measurements are then compared to a chart to determine the rating and assigned a filtration grade of 1 through 16. The other term used regarding filters is HEPA. HEPA stands for High Efficiency Particulate Air. It describes a filter that is able to trap 99.97% of particles that are 0.3 microns in size. The 0.3 micron size is referred to by scientists at the MPPS, or the Most Penetrating Particle Size. It is used as the standard because 0.3 microns has been determined to be the size of radioactive particles. This was discovered during World War II when the HEPA filter was developed to capture radioactive particles release during the creation of the atomic bomb. U.S Shotblast Parts and Service Corp offers three MERV levels of filters for your dust collector and the price is structured accordingly. MERV 11 $ 40.85 MERV 15 $ 54.00 MERV 16 $123.50 The MERV 11 is high quality and low cost. The MERV 15 is even higher quality and is rated just below HEPA efficiency. The MERV 16 is the highest rated MERV and is a HEPA filter, meaning it filters out 99.97% of particles 0.3 microns in size. Give U.S Shotblast Parts and Service Corp a call 1-888-842-6766 and let us help you select the proper MERV rated filter for your surface preparation needs.