.This is a blank tie tack, scatter pin also sometimes called a nail. It has a 11mm long post and 10mm PLASTIC pad for gluing things on. It is plastic but very tough, nail is embedded in well. We recommend these for use with heavier fabric or specifically with the spring loaded clutches. The reason is the post is a bit longer then the standard tie tack. Spring loaded clutches often need this extra length to grip properly. You can use these with a regular butterfly clutch, but distance between the back of the clutch and the back of the head of the tack will be be wider then what you might use for a scatter pins going on thin fabric. You might consider these longer tacks if the finished tacks will be worn on a jacket of something thick like that.... or actually as a Tie Tack where you need to go through several pieces of fabric. For thinner fabric see out other standard metal tie tack.