Head Gear AP4-XXX-9929 For Antra Auto Darkening Welding Helmets AH6 AH4 series Specially designed headband for more comfort. Smooth Headband Adjustment by PUSH&TWIST knob and washable sweat band. FITS MODEL AH6-XXX-XXXX, AH4-XXX-XXX, AH4-660-0000, AH4-660-212R AH6-360-0012 AH6-360-0018 AH5-350-001X