The Snap-On Tools CT4D 6-12 Volt Circuit Tester Tool is a high-quality, USA-made unit designed for automotive use. This tester is powered by batteries and is specifically designed to test 12V circuits. With a simple design and reliable performance, this circuit tester is a valuable tool for mechanics and car enthusiasts looking to diagnose electrical issues in vehicles. The Snap-On brand ensures durability and dependability, making this circuit tester a trusted choice for professionals in the automotive industry.