Specifications. 1,zinc alloy made 2,inner width: 19mm travel bags/backpack/laptop(computer) bag,suitcase,piggy bag used. bags or luggage accessoriesfitting trolley case/backpack/laptop(computer) bag,suitcase,piggy bag,travel case, travel bags used Specifications1,material,zinc alloy 2,inner width: 19mm .3. net weight, 7.5g/pcs. swivel hook buckle