Question about Einhell GP-EA 18/150 Li BL Solo

The Scheppach auger with a 30 cm diameter and 20 mm shaft does not fit the Einhell cordless auger, as this has a drill diameter of 150 mm (15 cm) and a different drill length. In addition, the supplied auger attachment for the Einhell auger can be changed without tools, but the shank holder is designed for the supplied auger, which does not have a 20 mm shank diameter. A 30 cm diameter is also significantly larger than the standard 15 cm attachment on the Einhell tool, which indicates compatibility problems.