Lens mount Kiev-19M - bayonet N. Working distance - 46.5 mm.
Aperture blinking and open metering supported. The standard lens Kiev-19M is MC Helios-81N 2/50. In post-Soviet times, the lens became known as Arsat H 2/50. It's just a rebranding.
There are no real differences. Interestingly, the name is written in Latin, and the letter denoting the type of mount - in Cyrillic.
This is exactly "N", not "H". The shutter is mechanical, lamellar with vertical movement of two pairs of metal lamellas.
Beats shutter speeds: 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, V. The camera is equipped with hot and wired sync contacts.
Viewfinder image field size - 23 × 35 mm, the viewfinder's area of view covers 93% of the frame area. Focusing screen type - Fresnel lens with frosted ring, micro-raster and Doden wedges. The weight of my copy without the lens is 664 grams.