Canon IV SB2 (1954): a Japanese copy of the Leicas 39mm screw mount (as the IIIf) : well sold camera; here with a Leica lens.
According the series number, this camera is a IV SB2 model; there are several variations of this model; it is a well built camera; the series compatible with the Leica 39mm screw mount started in 1951 and stopped in 1968.