The MERV 11 pleated filters incorporate a 100% synthetic MERV 11 (Minimum Efficiency Reporting Value), and can handle velocities up to 500 FPM. The filter pack is enclosed in a heavy-duty, die-cut frame that will not warp, crack, or distort under normal operating conditions. The MERV 11 filters accumulate heavier, more restrictive particles at the bottom of the pleats, leaving the sides open longer for effective filtration. The MERV 11 filter is engineered to provide maximum efficiency. In general, deeper pleats result in longer life and more time between change-outs. These filters can be used without modification in side-access filter housing or built-up filter bank. They offer better efficiency than conventional permanent or disposable flat filters. These are the perfect filters for commercial and industrial use.