Strong Material The garden auger bit head is made of premium manganese steel and the shank is made of A3 steel, durable and not easy to deform. The surface with glossy black painted finish well protects the garden drill bits from rust High Efficiency Spiral design ensures efficient digging and dumping of soil without difficulty. Use a low speed (slow) drill, then drill into the ground or suitable landscape, the auger bit easily digs a hole in seconds and works well even in a little hard ground. Noticed: Not suitable for large rocks or solid rocks Machine Suitable Both garden drill bits work great with any drill with a 3/8" or larger chuck. But it is better to use drills with a power of 18V or more (For the cordless drill at least 14V) in order to have a better digging experience and save labor time 2 Various Sizes This 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 in helping you create a nice little garden Wide Application These spiral drill bits are the professional landscaper's ideal choice, very suitable for planting bulbs, potted plants, vegetables, flowers, bare root trees and shrubs, till the soil, and mix seeds. After using, Always keep the drill bits clean in order for each best use This garden auger set is perfect for planting, seedlings, trees, shrubs, deep cultivation, concrete mixing, potting soil, irrigation trenches and more. This ground drill also makes it effortless to dig post holes or even take it on vacation to drill a hole in the sand to anchor your umbrella. It will be a good helper for you. Note : Keep the auger clears soil and debris when not in use. Note: We do not recommend using it for drilling through roots. If you find many roots in the ground while digging, we suggest you change your position. Delivery quantity: 2 piece