Durable & Stable: Made of quality carbon steel, it is durable and thick. It's not easy to break up. 10mm steel shaft with non-slip hex drive; 8 cm diameter x 30 cm length. Non-slip hex drive: With its hex end, this drill bit provides excellent grip in chucks. Good Garden Helper: Attaches to a standard electric or cordless drill. This spiral drill bit helps you dig deep into solid garden soil, saving you your effort and time. Easy to Use: The tip of this twist drill bit keeps it more stable when digging compacted soil. Varied Applications: This helical hole drill is the choice of professional landscapers for greatly increased efficiency when planting bulbs, potted plants, vegetables, flowers, bare-root trees and shrubs, tillable soils or gardening.