The MacBone K10 air filter is designed to be mounted next to the MacBone rooftop or vertical unit, and to connect, by flexible hose, directly to the unit's outside air inlet. As an inherent feature of their design, MacBone units take in 10% outside air while providing operator's cab ventilation and pressurization. This outside air inlet is supplied with a course filter, however, in dusty conditions, the finer filtration provided by the K10 may be desirable. The filter element supplied with the K10 is a Donaldson "Vacu Filter", model G070019, and is available from us or from any Donaldson distributor.