TrueSight Lens & Cartridge, External Safety, Clear, 5 1 4 x 4 1 2, Polycarbonate ORS NASCO Upper and lower tongs are Upper and lower tongs are made from a high copper alloy for maximum conductivity and strength Top and bottom tip insulators are a molded fiberglass compound and will withstand intensive heat impact Handles are molded from a durable glass filled nylon material with a good heat and impact resistance Oval point screw cable connection is standard on all models Rugged aluminum alloy body designed for handling ease Amber band pass for enhanced clarity of weld puddle Built in magnification lens Four independent sensors positioned to reduce possibility of blockage during weld Large separate buttons with LED indicator for Weld