All the benefits of RAM Prime PLUS Quick Snap-On Exchangeable Vision Chart.  Comes with one charts.  Additional Charts include Letters, Numbers, Landolt C, Tumbling E, ETDRS Chart Series, and Custom.  Includes One Snap-On Vision Chart, Carrier Frames, two Pinhole-Lens Clips, Magnetic Occluder, Trial Frames Pinhole Disc, Battery Charger, Lens Cloth.  Panoramic Pinhole Lens Clip, Low Vision Attachment (to 20/1600), additional Charts, Landyard Switch, and Adjustable Lanyard are available options at extra cost.  Consider 10 Year Extended Warranty.