4" square dark brown acorn finial, look great and also stops the birds landing on my posts.
I wasn't sure whether these would be any good after reading other reviews, yes they are hollow, but are strong. They find their own position when placed on top of a square post to centralize themselves. One screw to hold the bottom half of the acorn onto the base plate and into the post. I suppose if you used a power drill you could split the base , but very easy to fit if you take care what you are doing. I took the advice from another review and snipped off 1-2 mm of the locating pins, this was to ensure a snug fit once you place the top half of the acorn onto the part you have fitted already to the post.