Come and see our amazing products. The keychain for the survival whistle is made of aluminum alloy. No matter where you take them a day, this whistle key ring allows them to easily stay cautious and safe. There are many colors to choose from. The diameter of the whistle is about 0.31 inches and the length is about 1.85 inches. We welcome custom logos, please contact us. Pls confirm with us about the packing info, stock color and exact production time before placing your order.