Solid MaterialThe garden auger bit head is made of premium manganese steel and the shaft is made of A3 steel, durable and not easy to deform. The surface with a glossy black painted finish protects the garden drill bits well from rusting. High EfficiencySpiral design ensures efficient digging and soil dumping without difficulty. Use a drill at low speed (slow), then drill into the ground or suitable landscape, the auger drill bit easily digs a hole in seconds and works well even in the slightly hard soil. Note: Not suitable for large rocks or solid stones Suitable MachineBoth garden drill bits work perfectly with any drill with 3/8" or larger chuck. But you'd better use drills with 18V or higher power (For cordless drill at least 14V) for a better digging experience and saving labor time 2 Various SizesThis set contains two auger drill bits 40 x 220mm and 80 x 300mm. They are used to quickly dig a hole of 40mm/80mm in diameter, and 220mm/300mm in depth. It helps you plant many plants of different sizes, very useful to help you create a nice little garden Wide ApplicationThese spiral drill bits are the ideal choice for professional landscapers, well suited for planting bulbs, potted plants, vegetables, flowers, root trees bare trees and shrubs, cultivate the soil, and mix seeds. After using, always keep the drills clean for better use. Quantity delivered: 2 pieces. Product color: black. Product specification: 8*30 cm, 4*22 cm. Good quality product.