WhAeoy Mohs Hardness Test Kit- 4 Pack, 2-9 Scratch Tester Hardness Test Pen, Stainless Steel Mohs Hardness Picks, with Storage Box, Single Dual Head De-sign, for Mineral, Gemstone, Floor,A

Each hardness pen has writing needles with different hardnesses at both ends. The scales according to Mohs hardness are: 2&3, 4&5, 6&7, 8&9. Made of pure stainless steel, with good texture and exquisite appearance. There are 4 hardness pens in the box, each 155mm long. Hardness test kit is a multi-faceted shape carefully processed so that will be more convenient to use. The storage box is equipped with a grindstone striped plate magnet, and aluminum plates, brass plates and glass plates with different hardnesses can be used to identify the hardness of minerals. This hardness test pen is applicable for ceramic tile, floor, glass, mobile phone screen, mineral, concrete, etc.