The 18-35mm f/4-5.6 wide angle zoom lens was initially a kit lens option for the *ist series of dSLR cameras. The lens has now been discontinued, replaced in the lineup by the APS-C sized 16-45mm f/4 ED.
The lens name bears a long list of standards. SMC stands for Pentax's proprietary ''super multi-coating''; AL represents the lens' use of aspherical lens elements; FA explains the lens is autofocus-enabled, with a digital chip in the lens; and the J designation explains the lens is part of Pentax's budget series of lenses, with a plastic lens mount and no aperture ring. Read the whole review here