Hydac 306866 VM5D.0 V L24 Clogging Indicator H541ASD Compatible with Pump Type Air Compatible with Pump Type Air and Gas Operated Diaphragm 3 mil Color Clear Bag Closure Type None Width 32 in Height 44 in Max Load 75 lb Bottom Seal Type Star Scent Unscented Legend No Legend Package Configuration Flat Pack Bags per Roll 125 Rolls per Package 1 Item Trash Bags Package Quantity 125 It may be difficult to establish a reliable schedule for installing new elements because the rate of dirt ingression is not known Clogging indicators are warning devices that signal visually and or electrically that the filter element is filled with contaminants and should be changed or cleaned