Christie WU12K-M Projector Filter When your projector is exposed to more than normal amounts of dust, dirt or sand its performance can be reduced which can lead to sudden malfunction and/or maintenance downtime for the unit. In these extreme environments, coarse dust filters can protect your system and protect your investment.Each of the projectors listed below are designed to operate filter-free, but is equipped with two removable side panels that are designed to hold a filter, if required. Additional mounting equipment is not required.The Coarse Dust Filter Pack is suitable for all projectors listed below.Specifications Expected Life Up to 200-500 hours depending on environmental conditions Includes 1 Coarse Dust Filter