Bosch Professional 7 pcs. SelfCut Speed Spade Bit Set (for Wood, with Extender, 1/4 inch Hex Shank, Ø 16 - 32 mm, Accessories for Impact Drills) : Amazon.co.uk: DIY & Tools
Irwin 88820 Speedbor 1-1/4-Inch by 6-Inch Spade Drill Bit : Amazon.co.uk: DIY & Tools