Material: cow leather + sponge + glass. The mask is made of high quality materials and a sponge sight frame, which is durable, sweat-wicking, heat-resistant, breathable and very comfortable to wear. Features: It can effectively prevent skin flaps, welding slag, dust and other objects from invading the neck and face. The flip-up lens avoids frequent checking of the position of weld joints, making welding work more convenient and safe. The mask has a hook and loop on the back for quick and easy adjustment and adjustment size. The ideal accessory for complete welder protection. Helmet height: 32.5cm / 12.79 Helmet thickness: approx. 1.4mm / 0.55 Head circumference: approx. 60cm/23.62(LxW) Lens Dimensions: Approx. 10.8 x 4.5cm/4.25 x 1.77. Note: All dimensional markings are measured by hand, please allow small deviations. Due to different monitors, the color of the actual item may be slightly different from the pictures shown online. Thank you for understanding. The mask lens does not have an automatic dimming function.