1959 Pentax H2. There were 2 versions of the H2 released, the first bring in 1959 and a second version in 1961 that added meter coupling. Meter coupling can be identified by a notch being present beside the shutter speed dial, right beside the "T". So far. all of my H2s are version 1s, and this particular H2 has an extremely low serial number, presumably being from an early production run.
1959PentaxSilverH2AsahiAsahi Pentax H2
From Asahi Pentax - S / H Series