Note - This suggestion will be very limited on this specific vehicle’s history (In the context of why their was a version of the T-80UD with K1 ERA), this is because I have been unable to find anything specifically talking about its origins so instead I will refer to the history of the T-80UD itself.
Background & History
The T-80UD early is an early model of the T-80UD main battle tanks which were built at the Malyshev Factory in Ukraine in the late 1980’s as a response to the normal T-80’s habit of using lots of fuel due to it’s gas turbine engine resulting in the T-80UD which was a diesel powered version of the T-80.
Like the T-80U the T-80UD typically cam equipped with Kontakt 5 ERA however also like the T-80U the T-80UD appear to have had a early production vehicle which instead used the older Kontakt 1 ERA, and while I would love to explain why it was done I honestly can’t, since none of the sources I read through every mentioned why this was but mentioned it’s existence which is backed up by photos, though it’s likely that once the USSR collapsed they would they all seem to have been taken out of service.
From what information on these vehicles I can gather a small number of these vehicles were produced and once the Soviet Union had collapsed had a number or possibly all of them ended up in Russia though I have not been able to confirm if any ended up in Ukraine.
Like the standard T-80UD the vehicle mainly differed from the T-80U in its engine as it was powered by a 1,000 hp 6TD diesel engine which was capable of getting the vehicle to a top speed of 60 km/h forwards. Armed with the same 2A46M-1 gun as on the T-80U the T-80UD has the usual 28 rounds in the autoloader plus another 16 carried in the tank and of course the round that is already in the gun for a total 45 rounds, along with this the vehicle came with a 12.7mm NVST machine gun that was located atop the commanders hatch and the standard coaxial 7.62 PKT machine gun. As with the standard Soviet built T-80U the vehicle has access to a 2E42M1 two plain gun stabilizer for the main gun, the vehicle also has access to NVD’s for the entire crew as the vehicle does not have any FLIR systems.
Weight - 46 tons
Crew - 3
Engine - 1,000 hp 6TD diesel engine
Mobility - 60 km/h (Forwards)
Smoke grenades - 8 x 81mm Smoke Grenades
Main armament - 1 x 125mm 2A46M-1 smoothbore gun
Ammo - 45 rounds total (28 in autoloader + 17 additional rounds)
Commander MG - 1 x 12.7mm NVST machine gun
Ammo - 300 rounds
Coaxial MG - 1 x 7.62mm PKT machine gun
Ammo - 1,250 rounds
Armor - (Same as T-80UD but instead has Kontakt 1 ERA instead of Kontakt 5 ERA)