DescriptionThe vernier micrometer is widely used for measuring of industrial accessories, handicraft, pearls and jewels. It can measure inside, outside, depth and step size with two sets of jaws and the probe. I believe that will be a good idea, if you could give your children a handmade necklace as birthday gift, which is made of pearls in oysters. The micrometer caliper will help you a lot, it is a good partner of pearl drill.Features- Color: As shown. - Material: Stainless Steel. - Size: 24.5x9.3x3cm / 9.6x3.7x1.2inch(LxWxH). - Extra large LCD screen for easy and clear reading.- The metric caliper is 0-6 inch / 150mm, you can test inner diameter, external diameter, depth, length, width by it.- There are 3 button on it, one is on / off, one is mm / inch switch, the last is back to zero. You can slide it to anywhere and reset it to zero by zero button.- The gauge caliper range is 0-6 inch / 0-150mm. The gauge caliper can be accurate to + / - 0.02mm / 0.001 inch.