This is a 5-piece High Speed Steel twist drill bit set in sizes 4mm, 5mm, 6mm, 8mm, and 10mm. Made from HSS for durability, sharpness and heat resistance, these spiral flute bits are designed for drilling into metal, wood, and plastic. Packed in a clear yellow storage case with labeled slots for easy size identification and organization. Ideal for workshop, construction, and DIY use with any power drill.