Abstract: A multistage filter cartridge includes a generally circular outer filtering stage composed of a melt blown polypropylene material having an outer surface and an inner surface and an inner diameter and an outer diameter, and a generally circular inner filtering stage composed of carbon and a binder material forming a carbon block having an outer surface and an inner surface and an inner diameter and an outer diameter. A first void is disposed between the inner surface of the outer layer and the outer surface of the inner layer, and a second void within the inner surface of the carbon block, said voids being filled with granular, filtering material.

Abstract: Apparatus for sensing the arrival of a motor vehicle at the pick-up window of a drive-thru business and providing a visual display of the length of time that the motor vehicle is present at the window. Visual and audible alarms apprise operating personnel that the vehicle has been present for a predetermined length of time. The apparatus also totals and displays the number of vehicles as well as the total duration of stay of all vehicles arriving at the pick-up window.The motor vehicles are sensed by means of a vertically oriented rectangular loop detector positioned beneath the pick-up window adjacent the vehicle approach lane. The detector senses the metallic sides of the approaching vehicle, and is shielded to prevent spurious signals.The apparatus finds particular application for improving the working efficiency of operating personnel of the drive-in business.