Yes! A pair of cufflinks with mechanical parts :D a rotating bar that clicks into place, and it works so well, you can put the cufflink into your shirt with one hand. Assemble it yourself, no tools required, it even snaps at 90 degrees increments! So enough glee about mechanical moving parts, what is the design about? The buckler is a small shield that was worn on the off side hand, particularly useful for protecting your (one handed) sword hand. When fighting with a buckler, the outer measure of fighting becomes significantly smaller and grappling and locking becomes easier. I occasionally fight with a buckler myself, and it really helps getting closer to your opponent.
This design of this buckler has been loosely based on a 1317 AD drawing from the "Legende de Saint Denis". The original probably has no holes, is a bit bigger (around 30cm) and was therefore too big to be worn as a cufflink (which is a 16th century invention). I have not intended any symbol to be portrayed here, other than a buckler.