The JJunLiM Universal Welding Helmet Lenses are made of clear polycarbonate material, measuring 4.5" x 5.25", and come in a quantity of 20. These lenses are designed to fit welding helmets and provide protection during welding processes. The polycarbonate material offers durability and resistance to impact, ensuring the safety of the user's eyes and face while working with welding equipment. With a part number of BW5852, these universal welding helmet lenses are a reliable and essential accessory for welders in various industrial and manufacturing settings.