Insight Digital Variable ADF Welding Helmet, 9 to 13 Shade, Black, Ratchet, 3.93 in x 2.36 in Window ORS NASCO Designed for precision metal fasteners Designed for precision metal fasteners under 3 4" Protects threads from rust and corrosion Removable with hand tools Chain holds and locks around any shape or size Turn screw to adjust pressure and fit Constructed of high grade heat treated alloy steel Guarded release trigger quickly unlocks and protects from accidental release Replacement chain available and sold separately Variable shades to shield and protect eyes from radiant energy during weld Viewing area offers unobstructed views during all stages of welding process without lifting hood Sensitivity and delay adjustments for different tasks and durations Weld and grind modes Four independent sensors reduce blockage possibility