DIN 911 hex key ball end
This key is hexagonal at the short end like conventional keys, but it has a ball at the long end. This end allows for tightening when the key is not completely aligned with the screw and access is difficult due to lack of space. Made of chromium-vanadium steel, which improves wear resistance, according to DIN 911 standards.
Chrome vanadium steel 58 CrV4 (1.8161)