The K20D was Pentax's second generation of semi-pro DSLR, replacing the K10D in January of 2008.
While its $1,300 MSRP put it head to head with Canon's EOS 40D, the price leader in the category, its Samsung-sourced 14.6 megapixel CMOS sensor offered almost half again the resolution, making it the highest-resolution APS-C camera on the market at the time (tied, of course, with its Samsung-badged clone, the GX-20.)
It was Pentax's top-of-the-line DSLR, but the line in question only consisted of the K20D and the cheaper, lower-resolution K200D.
The mode dial has the usual full-auto (green rectangle) and PASM modes, along with a couple unique-to-Pentax settings. The "TAv" position is "Shutter and Aperture Priority", where the user operates the front and rear dials to manually select the shutter speed and aperture size and the camera automatically adjusts the ISO to try and get the best exposure. "Sv" is "Sensitivity Priority" and functions like Program mode except the rear dial is used to set ISO on the fly, which is useful when operating in an environment where lighting conditions might vary wildly.
It's a physically small camera in the category; noticeably smaller than the Canon, Nikon, and Olympus entries and even slightly svelter than the Sony a700.
It's missing some typical buttons, such as ISO, instead using a combination of the "Fn" button and on-screen menus to select these settings.
The battery and memory card doors are securely latched and the whole camera feels quite rugged. With its 14.6MP sensor and an ISO range from 100 to 3200 (expandable to 6400), the K20D still holds up quite well today and nice used ones can be found for well under two hundo.