Features:Pins size: 10 mm in diameter, 9 mm in length; Material: PVC; Rubber pin keeper size: 10.6 mm in diameter, 7.6 mm in height.Practical shape: protruding half round shape handle on the pin back is designed for easy grasp, thus you can be convenient to take on.Tight rubber pin back: the PVC pin back is tight and they are not easy to fall off; Each pin back has a hole which is for tie tack pin.Multiple purpose: good for jewelry making; You also can use tie back to fix object, such as photos, fabrics, cloth, map, scrapbook, etc.Replacement for the lost pin back: can be the pin clutch backs, fits for all lapel pins, tie tacks, service bars and jewelry. Package Includes:100 Set/Box Backing Pins Specifications:Material: PVCColor: Black/Pink/BluePins Size:Approx.10X9mm/0.39x0.35inchPin Keeper : Approx.10.6x7.6mm/0.42x0.3inch note:Please allow 1-2cm errors due to manual measurement,pls make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item."