Made of heat treated chrome molybdenum steel.
Allows quick removal with the propellers that act like a screw.
Dimensions :
N ? 1 1 / 8 "-1 / 4" (M 3 -6)
N ? 2 1 / 4 "" - 5 / 16 "(M 6 -8)
N ? 3 5 / 16 "-7/16" (M 8 -11)
N ? 4 7 / 16 "-9/16" (M 11-14)
N ? 5 9 / 16 "-3 / 4" (M 14-18) "
