HERE'S A TRICK YOU CAN STICK IN YOUR BAG. When welding in clear water and silty or muddy water the need to change the shade of your lens follow those conditions. Right? So when a hand broke my glass 6x6 which i knew would happen I got a shaded grinders face shield cut it to size and doubled it up. the water was like mud. 3 to 5" vis at times. never greater than a foot. That combination was perfect. Then a month later i was welding in clear water So I added another layer of this plastic lens. Just score it and pop it. It breaks off really nice. You'll never break another lense. With a little work you can salvage about 15ea. 2 x 4 lenses or 6 ea 6 x 6 lenses. from one 12 dollar shield. This is a grinding and cutting shield so its a UV rated material.