【High Quality Material】Made of sturdy steel, durable to use. With a glossy black painted finish, the cultivator drill bit is not easy to rust. 【Fast Digging】Easily dig through most types of soil, even clay and rock. Makes planting jobs much easier and faster, save your back and let the spiral planter do the work! 【Spiral Drill Bit Size】8cm diameter x 30cm length (3.1in x 11.8in) planter bulb with anti-slip hex drive, works with 10mm (3/8") or larger drill. 【Compatible】Use an 18V or larger drill at low (slow) speed, drill into the soil or applicable landscape straight down for 30cm and lift out of the hole; For cordless drills, a minimum 14V drill is recommended. 【Perfect for】Suitable for professionals and home DIY projects, planting flower bulbs, bedding plants, grass plugs and nursery seedlings, fertilizing shrubs and trees for deep water aeration and even weed and root removal.