The APG8735SGC is a solar powered helmet uses that uses CR2450 replacement battery backup power. It features 4 arc sensors and an increased viewing area of 3.78 in. x 2.09 in. Adjust your shade control from 9 to 13 or put it in Grind mode to prevent darkening while grinding. Made to fit right, the 6-point adjustable head gear allows you to make it fit your way. with ANSI and CSA approval, the Metal Man 8735SGC Series Auto-Darkening helmet is safe, functional, and attractive to users.