FUNCTION: This set replaces 50 individual drill bits.Twin flute design gives you faster, smoother cutting.3-sided shank won't slip in your drill chuck.Cobalt coated for smoother cutting and cooler. PERFORMANCE: Titanium coated to reduce friction and cool. DESIGN: The large size bit has a 3-sided shank and the small bits have a shank hexagonal to prevent slipping in the drill chuck SPECIAL: Automatically deburrs holes while drilling. DURABLE: Long Life High Speed Steel. Includes a protective padded aluminum case. Features: FUNCTION: This set replaces 50 individual drill bits.Two flute design gives you faster and smoother cutting. 3-sided shank (TRI-FLAT) won't slip in your drill chuck.Cobalt coated for a smoother, cooler cut. PERFORMANCE: Titanium coated for reduced friction and cooling. DESIGN: The large bit has a 3-sided shank and the small bits have a hex shank to prevent slipping in the drill chuck SPECIAL: Deburrs holes automatically while drilling. DURABLE: Long Life High Speed Steel. Includes a protective padded aluminum case. Features: Package size: 15cm*10.5cm*4.2cm (L*W*H) Package included: 1 x 1/4-1-3/8 step drill 1 x 3/16-7/8 step drill 1 x 1/4-3/4 step drill 1 x 1/8-1/2 step drill 1 x 3/16-1/2 step drill 1 x aluminum box