安全螺母 meaning in English

safety nut

Couplings for compressed air - claw coupling , 42 mm internal width , with securing nut - coupling with male , female and hose connection ends , joint ring
压缩空气匹配件.爪状匹配件,带安全螺母内部宽度42mm ,
Couplings for compressed air - claw coupling , 42 mm internal width , without securing nut - coupling with male , female , hose and closure connection ends , rotary claw couplings , joint ring
压缩空气匹配件.爪状匹配件,无安全螺母的42mm内宽,凸