Platinum Tone Alloy Key Clasp Findings, Ring. Size: about 20mm in diameter, 12mm inner diameter, 4mm thick. This is a simple clasp that can be a key chain. It has a good tension and spring for many design applications. Base metal is alloy. So buy this and Get 55% OFF 2 pcs Platinum Tone Alloy Key Clasp Findings for $0.79 @PandaHall