Otto Frei–BORE Jewelers Drill Bit Basic Kit with 150 HSS Twist Drills Sizes #51–#80 Jura by GRS 10x Achromatic Lens System: The

10x Achromatic Lens System: The achromatic lens eliminates color aberration by combining multiple coated lenses cemented together using different types of glass

Profile Type Half-Round Low Dome Factory Profile Number SP67 Height-to-Width Ratio 33% (height is 1/3 of width) Number of Holes 31 Largest Hole 12 mm × 4 mm Smallest Hole 9 mm × 3 mm Material Hardened steel Country of Origin Italy Compatible Metals Gold

Set of 16 burs supplied in a plastic bur storage tray

Glardon-Vallorbe Revere needle file set with 12 files for precision metalwork

One tip is curved to cradle the shank

Otto Frei–BORE Jewelers Drill Bit Basic Kit with 150 HSS Twist Drills Sizes #51–#80 Jura by GRS 10x Achromatic Lens System: TheThe Otto FreiBORE Jewelers Drill Bit Basic Kit combines the precision of HSS twist drills with the smart organization of the BORE drill holder by Nashef Designs. This complete master kit includes 150 HSS twist drills in sizes #51 through #80, neatly arranged in a 3D printed organizer with labeled compartments and a clear viewing window. Compact and thoughtfully engineered, it keeps your most frequently used micro drill sizes visible, protected, and