416356 Prym Plastic Clip Buckles 30 mm, Black – 1 Piece. These Prym 416356 clip buckles are the perfect closure for backpacks, suitcases, shoulder straps, leashes, belts, and clothing such as work trousers. Made of highly resistant plastic, they guarantee reliability and durability over time. The two hooks at the top of the buckles are used to adjust the straps. Available in various sizes.