Length: 2mm Width: 5.5mm Height: 4.1 Hole size: 3mm x 2.5mm Sold IndividuallyMaterial: Zinc plated with gold, shiny clear coatedOrigin: European UnionFree of lead, nickel, cadmium. Hypoallergenic. This slider can be used instead of o-rings to hold other spacers and beads in place. Once you have everything in place on the leather simple crimp the back end of the slider with a pointed metal tool so that it crimps down and holds everthing in place.