4inch (10cm) wide by 28inch (70cm) long allows you to be standing whilst drilling the holes in soil.
Being a larger auger it is recommend you use a Higher Powered Variable Speed 240v or petrol powered Drill (13mm chuck) with side handle and clutch to protect you against kickback.
It has a common 13mm (1/2inch) hex head.

NOTE: We don't generally recommend this size Power Planter for home garden use. This is a professional grade auger used by Landscapers and does require a higher spec Drill and previous knowledge with power tools.
For DIY home garden Power Planters, please see the Home Gardener Range at this link.

Popular uses are:

Rapidly planting 4inch potted colour or similar pot size. (Also suitable for planting smaller tubestock where you want to improve the soil by adding compost to the hole)
Drilling multiple holes and moving sideways between them to cultivate the soil deeply
Drilling a 100mm diameter tunnel under a path
Tree Planting and applying fertiliser tablets deep into soil.
Post Hole digging to exactly 4inches wide with minimal external soil disturbance.
Mixing barrow loads of Concrete/mortar
Mixing fertiliser into soil mix
Mixing paint
Digging a trench for plumbing and irrigation - by drilling holes to required depth consecutively along the line and then remove any remaining soft soil with a trenching shovel or by hand.

N.B. We hope it is pretty obvious... but we better say it - The price does not include the Dewalt Drill shown in the demonstration images. The Power Planter can fit onto any standard Australian drills with a 13mm chuck. (eg. Ryobi, Bosch, Black and Decker, Hitachi, etc )

Power Planter 428H