Come and see our amazing products. These emergency whistles uses aluminum alloy and metal keychain, durable and non-toxic material, not easy to break, fade or corrode, double anodized treatment.length of these loud whistles is 4.7 cm/ 1.85 inches, diameter of the these whistles is 0.9 cm/ 0.35 inches, suitable size for your use and storage Pls confirm with us about the packing info, stock color and exact production time before placing your order.