Concerning DCH5090EL. My son bought one in around November 2012and then he bought me one in February 2014.On the box which is labeled as a DCH5090EL feature number 4 lists a Dust Filter. On the side of box describes advantage of filter. Heated has notches where one would go but neither of us got a filter. Am we missing them? Thanks. E-mail ruthpalermo10@gmail.com.