KOTARBAU® U-post support, 140 mm, U-shape for doweling, square wood posts, base plate, anchor hot-dip galvanised : Amazon.co.uk: DIY & Tools
Gartenwelt Riegelsberger U-Shaped Post Support Stable 71 mm Hot-Dip Galvanised Steel for Posts 70 x 70 mm : Amazon.de: DIY & Tools
GAH-Alberts Anchor Post U, to screw in, Hot-Dip Galvanised Steel, 217631 : Industrial & Scientific - Amazon.com
ADGO TT Bracket Base Post 90 mm Screw for Fence Post hot dip Galvanized Sliding Sleeve Sleeve Support Bracket Floor Sleeve Slide-in Floor Sleeve Steel Base Silver : Amazon.co.uk: DIY & Tools