This is a double hinged lock for chain can be used for Cuban Link or any type of chain. It has double movement easy flexibility it’s ready for cast . if you need any other size, I can make it. I have 40 years experience as a jeweler and now 10 as a designer, I speak perfect English and Spanish and I can make any model design you need at a very reasonable rate I have a lot of experience making hip-hop jewelry also watches any brand I could make any part you need if you need my service I’ll be happy to work with you