Three "400" series Oregons top the new line. The $639 Oregon 400T features pre-loaded topo maps, 3D map view, barometric altimeter (supplements GPS altitude calculations for better accuracy). It lets you exchange tracks, waypoints, routes, and geocaches wirelessly between similar units. Plug new maps and marine charts into its SD card slot. The $639 400i is similar to the 400t, but designed for freshwater use, and comes with a US inland lakes detail mapset, rather than land topo maps. Map detail includes depth contours, boat ramps, and mile markers for thousands of lakes. The $639 400c is for saltwater use, include charts of coastal US and the Bahamas. The $533 Oregon 300 is similar to the 400s, but does not come with any preloaded detail maps, just a basemap. The $479 Oregon 200 does not come with preloaded detail maps, and lacks the barometric altimeter, electronic compass, and ability to do wireless unit-to-unit data transfers. It does, however, have the same size and quality color touchscreen.