Deko MZ Series solar welding mask (model MZ224). Polypropylene helmet with a viewing area of about 3.64 inch by 1.67 inch (92.5 mm x 42.5 mm) and a cartridge size roughly 11.8 inch x 8.7 inch x 8.5 inch. Powered by a lithium battery plus solar cells for extended operation (over 5,000 welding hours), it features auto-darkening with adjustable switch time from 0.1 s to 1.0 s and a sensitivity around 0.00004 s.