safety is a top priority, and this tool is equipped with a CAT IV 1000V rating, protecting you from electrical shock. With the added benefit of self-checking functionality, you can rest assured that the tester is always working at its best. The bright LED light and loud buzzer provide immediate alerts when voltage is present, helping you stay informed and safe. Plus, if you prefer a quieter work environment, you can disable the sound by holding the button for 3 seconds.