The emf meter is convenient and practical, with excellent texture, and can serve you for a long time without being easily . The craftsmanship can serve you well without breaking easily. This emf meter is a very practical and reliable for your needs. Features -Color:Black -Material:ABS -Size:15.00X5.50X3.00cm/5.89X2.16X1.18in -Power supply: 1 X 9V battery (not included) -There are 5 LEDs, each representing a field strength range as follows: Dark Green - "normal" area - normal background field. 0 to 1.5 Green - "low" zone - low level field. 1.5 to 2.5 Yellow - "Warning" area - medium field. 2.5 to 10 Orange - "high" zone - high field. 10 to 20 Red - "Warning" zone - extremely high field. 20+ - LED indicator light to show different field values, convenient and practical to use. - Portable handheld design, easy to carry, easy to use. It can measure wide range. - Can be used in electromagnetic field detection of , furniture, antiques, building materials, decorations, food, etc. - Note: this emf meter can only measure field and electric field, cannot detect field. - Scientific design, high strength, high hardness, and excellent durability, it will easily meet your needs. Package list: 3 x meter