DURABLE MATERIAL: The keychain ring is made of iron, which is strong and durable. And the silver-toned nickel plating makes them shiny and smooth on the surface and edges. .SIZE DETAILS: The size of Keyrings for Crafts is 1" (25mm) and the chain is 1" (25mm) long, the jump ring is 3/8" (8mm) in diameter. .KEYRING MAKING KIT: A total of 100 Pcs 25mm key rings with chain and 100 Pcs jump rings. There are enough quantities to meet your daily needs. At the same time, the key ring can be reused, which can reduce waste. .EASY TO USE: Each key chain comes with a separate jump ring, you don't have to struggle to open to connect things, easy for you to attach your pendant to, easy to install and make your DIY projects easy.