Strv 103D
In the mid-1990s, as the Swedish armed forces were looking for a new main battle tank, one Strv 103C was upgraded into the Strv 103D. The major changes were the installation of fire-control computer, thermal viewers for both the gunner and the commander, allowing the crew to fight at night-time and in bad weather conditions, and the installation of passive light enhancers for driving. Some minor changes to the suspension system and engine were also made.
This prototype was used during the trials for the new main battle tank system for the Swedish armed forces alongside all the other tanks tested. For a few years this prototype was even tested under remote control. The only Strv 103D ever built is today on display at the Axvall armor museum, together with some 103C models. They are all still in running order.
Read more about this topic: Stridsvagn 103, History