Auto-darkening welding helmet/visor (Kings Sutton OX17)

"Clarke-Weld" welding helmet, screen fairly scuffed but still good enough (see pic) and auto-darkening function works really well. The only problem is the head band tightening mechanism slips - fine for most jobs but if you're leaning over e.g. under a car, it tends to fall off! Would probably be best to set it tight for user's head then glue the adjuster in place. I only thought of that after buying another one! Kings Sutton.