1. and durable:The olecranon hooks are made of zinc alloy, the surface and no sharp round edges design is friendly for carrying, they are durable for many and long-term using, the black coating can definitely prevent rust. 2. Easy to carry:These are much lightweight enlarged mouth clips,easy to carry and use, you can take these small clips with you all the time during your daily commuting, traveling, walking, hiking and many more. 3. The umbrella cord clamp is sturdy and durable, sturdy steel structure, strong elasticity, no sharp or jagged edges. 4. The spring-loaded connector is suitable for straps, umbrella , flashlights, keychains and other items. 5. Mini spring buckle, small fully functional, can be used for outdoor activities, such as fishing, hiking and camping. Inner diameter: 25mm Material:Zinc alloy colour:black Package Contents: 15 * Olecranon Hook Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.