50 Black Safety (BREAKAWAY) Buckles 3/8" (10mm). Contoured Side-Release. Good for Cat Collars! These are Safety / Breakaway / Pull-Apart Buckles. They are designed to pull apart under tension (approx. 2 kg). Not for use with leashes. Great for Cat Collars. If the cat collar catches on something, the cat's struggling action will cause the buckle to open, freeing the cat. Great for children's bracelets or bracelets for those working around moving machinery. The prongs on the male half are rounded and lack the hooks which are present on normal buckles. Buckles: 1.14 inches (29mm) long and 0.59 inches (15mm) wide at the widest point.