PROCESS OF USE: Scope of application: suitable for ac current detecting12-250v dc simply zero line detection, ac current breakpoint phase line, as well as non-live on-off LED drivers will represent: LED switch is easy to push convenient to use. FIRST SAFETY: It sends alarms by light. When voltage is detected, thewarming light turns on. NON-CONTACT: With inductive NCV probe for alternating voltage; Simply place the tip near a terminal strip, outlet, or power cord. When the tip turns on the light. You know there is current tension. The live can automatically detect the conductor or neutral. Ideal for breakpoint testing. Practical circuit tester for electricians, homeowners. PORTABLE: in insulating shell, the clip on the back is easy to hang to carry. DESCRIPTION: Product features: night vision lamp with lighting Material: Vanadium alloy steel / ABS plastic insulation Battery model: X3 AG10 (1.5V) (batteries included) Product size: 143mm X 26mm X 18.7mm (5.63in X 1.02in X 0.73in) Package includes: 1pc * test pen NOTE: 1.1 inch = 2.45cm / 1cm? 0.393inch 2.please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the product.