The Entangled Pins Challenge Metal Brain Teaser Puzzle is an excellent puzzle that has been around for many years. It is often sold as one of a set of several puzzles. It is also often made of a much lighter wire and for that reason can be properly called a wire puzzle. This one is identical except for being made with a heavy, 1/4 inch wire or rod, putting it in the class of a tavern or cast metal puzzle. It is high quality and appears to be stainless steel. It will withstand lots of abuse without being bent, or destroyed. As is common with all brainteaser wire or metal puzzles, minimal force is all that is required to solve it. It certainly qualifies as a medium, difficulty, non-intimidating puzzle for all skills and ages. You can purchase this puzzle at Amazon.