PT-1 vz. 1932
Tank sighting periscope with magnification 2,5, clearance 36 and field of view 26º, used for target acquisition on tank guns pattern 1932 of 45 mm calibre (K20) or pattern 1927/32 of 76.2 mm calibre (KT-28), used e.g. BT-5, BT-7, BT-7A, T-26-33, T-26-35, T-26-38, T-28, T-35, BA-6/6M, and BA-10.
The vehicles armed with the 1938 K20 pattern modernization used the PT-4.
Source
Soljankin A.G.,Pavlov M.V.,Pavlov I.V.,Zheltov I.G.: Otechestvennye bronirovannye machiny XX. vek, part 1. 1905-1941, Eksprint, Moscow 2002
Author's archive
Tank sighting periscope with magnification 2,5, clearance 36 and field of view 26º, used for target acquisition on tank guns pattern 1932 of 45 mm calibre (K20) or pattern 1927/32 of 76.2 mm calibre (KT-28), used e.g. BT-5, BT-7, BT-7A, T-26-33, T-26-35, T-26-38, T-28, T-35, BA-6/6M, and BA-10.
The vehicles armed with the 1938 K20 pattern modernization used the PT-4.
Source
Soljankin A.G.,Pavlov M.V.,Pavlov I.V.,Zheltov I.G.: Otechestvennye bronirovannye machiny XX. vek, part 1. 1905-1941, Eksprint, Moscow 2002
Author's archive