G-Suit
The G-Suit is a combat uniform for pilots to allow them to resist centrifugal forces (i.e. G-force) in maneuvers better. It prevents blackouts and loss of consciousness (LOC).
Active service of the G-suits started in WW2 in great numbers with the USAAF and after the war with RAF & RN jet pilots. It later became an integral part of the modern air force around the world with the advent of the jet age.
In War Thunder, G-Suit is first available for research in various American mid-to-late war fighters. It later became available for every post-war jet aircraft. When equipped with G-Suit, the pilot will be able to resist the G-force better than without one, thus lowering the chance of blacking out especially for a low-leveled crew.