DeWalt Rapid wood/Forstner drill, 117 mm diameter (suitable for use in drills, battery cable, for clean and accurate breakthrough holes in hard and soft wood, wooden floorboards, old building ceilings), DT4590 :
Forstner bit Diameter 25 30; Ø 35 mm with Centring Tip for choice for Blind Hinges Ast Alpen, White : Amazon.de: DIY & Tools