Features Efficient Cooling with Air Holes: The concrete grinding wheel features air holes that maintain and cool the cutting pattern, reducing wear and Features: 1、Using materials and fine grinding process makes the cutting edge more sharp. 2、Drill bit has a large scraps discharge space, little resistance and smooth. 3、Reduce cutting force and broken drill to improve the quality of hole wall. 4、Easy to change out and do a great job cutting through the PCB for solder holes. 5、Come with a great storage container, easy to find and grab the drill bit you need. Specification: Features: 1. Using materials and fine grinding process makes the cutting edge more sharp. 2. Drill bit has a large scraps discharge space, little resistance and smooth. 3. Reduce cutting force and broken drill to improve the quality of hole wall. 4. Easy to change out and do a great job cutting through the PCB for solder holes. 5. Come with a great storage container, easy to find and grab the drill bit you need. Specification: Material: Tungsten Carbide Quantity: 10pcs Storage Box Dimensions: 88*51*10mm/3.46*2.01*0.39in Cutting Edge Diameter: 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0mm Weight: Approx. 42g Package Includes: 10 x Drill Bits(The color of the ring is random) 1 x Storage Box Note: Due to the difference between the monitors and light effect, the picture may not reflect the actual color of the item. Thank you for your understanding. Package List