Specifications: Item Type: Handheld Tester Product Material: Plastic Product Application: Household Scope of application: Most scenarios Battery Type: 9V Alkaline Batteries x 2) Ships with matching batteries) Battery Model: 6F22 Battery Capacity: 60mah Product Size: Approx. 6 x 19.5cm / 2.4 x 7.7 inches How to use: 1.Insert the battery 2. Press the ON button 3. Inspection work range: 1. It can detect the broken edges of thin and small knits, clothing, socks, clothing, leather, leather shoes, etc., and can quickly find the right iron needle falling from the broken edge. 2. It can be used to detect ferromagnetic impurities in clothing accessories such as hardware buttons.High sensitivity is equivalent to 8-10 degrees, low sensitivity level is equivalent to 5-8 needles) 0.5-0.8 mm high sensitivity detection is suitable for fiber detection, low sensitivity is suitable for fiber detection, 0.9-1.2mm low metal zipper and shoe buckle, for applications requiring leather and use nail type detection probe. 3. Detect ferromagnetic materials in pharmaceuticals, foods, and chemical materials 4. You can check the presence of nails, steel bars and pies.Pais-in wood, wall, table 5. It can be used to confirm whether the iron inside is not penetrated into the human body, animal, or other parts of the work