Original sentence: The 1PN22M1 dual mode sight has a maximum range of  at night which increases to  with the use of the infra-red searchlight.The 1PN22M2 sight has two day scales for the two projectiles - one from  to  and the other from  to.The gunner has a dual mode (day/night) 1PN22M1 6x/6.7x magnification image intensifying monocular periscope sight, four day periscope vision blocks, an optical rangefinder and a OU-3GK  removable infrared or white-light searchlight.The gunner's 1PN22M1 sight was replaced by the 1PN22M2 sight with additional OG scale for the OG-15V HE-Frag rounds in the Ob'yekt 765Sp3 produced from July 1974
Edited sentence: The 1PN22M1 sight has a maximum range of  at night,  with the use of the infra-red searchlight.The gunner has a dual mode (day/night) 1PN22M1 6x/6.7x magnification image intensifying monocular periscope sight, four day-use periscope vision blocks, an optical rangefinder and a OU-3GK  removable infrared or white-light searchlight.The new sight has two day scales for the two projectiles - one from   and the other from.The original sight was replaced with the 1PN22M2, which has an additional scale for the OG-15V HE-Frag rounds used by the Ob'yekt 765Sp3, produced from July 1974