Brass Monkey Four. Just a single hole at the end of each piece differentiate it from Brass Monkey One, Two and Three. The absence of a single ring differentiates from Brass Monkey Five. Like the previous puzzles it weighs almost 800g (1.1 lbs). Each piece is 70mm long and has a diameter of 19mm. This is a puzzler's puzzle. Perfect for fooling those who think they have seen it before. It looks like a standard interlocking Burr. It isn't. It makes a perfect quartet with it's predecessors. This used to be the latest in the Brass Monkey Series but it will soon be joined by Brass Monkey Five.