Hop-up rubber from Guarder.
50° for guns with the output velocity bellow 110 m/s
60° for guns with the output velocity 110 – 120 m/s
70° for guns with the output velocity 120 – 140 m/s
75° for guns with the output velocity 140 – 160 m/s
80° for guns with the output velocity above 160 m/s