Insulation testers are specialized electrical testing devices used to measure the integrity of insulation in wires, cables, and electrical equipment. These tools apply high voltage to detect leakage current, ensuring safety and compliance with industry standards. Common in maintenance, manufacturing, and utility sectors, they help prevent electrical failures by identifying weak or degraded insulation. Features often include adjustable test voltages, digital displays, and rugged designs for industrial environments. Brands like Megger, Fluke, and Hioki offer models tailored for various applications, from routine inspections to high-voltage testing.