sentences:  Included are a direct fire anti-tank telescope, a panoramic periscopic indirect-fire sight (a dial sight) in a reciprocating mounting, an angle of sight scale, and a range drum engraved with the range (distance) scale, coupled to a mounted elevation levelling bubble.The range drum enables the standard Soviet technique of semi-direct fire when the piece is laid visually on the target and the range set on the range drum.An APN-3 was later provided for direct fire at night in place of the day telescope.