The new Cat D series hydraulic mini excavators — models 303.5D CR, 304D CR, 305D CR and 305.5D CR (pictured) feature a redesigned work-tool coupler, load-sensing hydraulics and engines that meet Tier 4-interim and E.U. Stage 3A emissions regulations. Increased-width undercarriages for the 303.5D CR and 304D CR and heavier counterweights for the 305D CR and 305.5 D CR enhance machine stability, increase lift capacity, and enhance use of reach and digging forces. A new pin-grabber-type coupler combines positive work-tool retention with a design that is designed to maintain tight tolerances between coupler and tool, reducing wear.