Your source is T 90 btvt narod ru Retrieved April 11 2014 90 Retrieved 15 November 2014 John Pike T 90 Retrieved 15 November 2014 However last two have same figure as global security and BTVT is not reliable source for Russian armour protection although it does have a lot of information about Russian armors For example BTVT claims that the protection of M1A1 abrams is 400 450 mm KE but in reality it was 600 mm according to Steven Zaloga and the Soviet Intelligence