Timber Technical Information 90mm x 90mm (3" x 3") 85mm x 120mm (3" x 4") 110mm x 110mm (4" x 4") Finish the Post with a Post cap These Fence post caps form a decorative finish to either a fence post or decking balustrade post. They are tanalised (Pressure treated) and smooth planed with a chamfered edge for a visually pleasing result.