It is believed this was an improvised weapon, with common origins cited as bridle bits for horses and livestock, Harness rings for reins, and metal hinges for gates and doors. How the weapon was formalized is still up for debate. They were usually worn in pairs.
Some versions were rings with a wooden peg attached on top. The ends were exposed and were usually sharp which made them effective for paralyzing and even killing enemies quickly and without leaving a trace. They were easily hidden in the fists and were very lightweight and portable.