HSS - High Speed Steel ensures excellent durability and sharpness, reduces friction and runs cooler. FIT YOUR NEEDS - With drill bits we provide, you can handle different types of diameter holes, saving you a lot of trouble. Great for metal/wood/plastic countersinks. Suitable DIY and general construction/engineering use. DESIGN - Durable and durable. The dual flute design provides a smoother cut, allowing material particles to escape easily for a cleaner drilling operation. Convenient Organization: An aluminum box is included in the metal kit for easy storage and organization, no need to worry about it falling down. SET INCLUDES - The drill bit set includes five universal sizes that fit most on the market. Material: high speed steel Color as shown Package Contents: 5 x step drill 1 x center punch Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.