Four Hole Back Plate for 40mm upright
Extreme

Four hole 8mm galvanised back plate.

51X51 back plate to suit 40mm tall crossmember with a 40mm wide upright

51X61 back plate to suit 50mm tall crossmember with a 40mm wide upright

51X71 back plate to suit 60mm tall crossmember with a 40mm wide upright

51X91 back plate to suit 80mm tall crossmember with a 40mm wide upright

These can also be used to mount various box sections together with the correct u bolt