HairDo is available in both 100% fine human hair and Kanekalon Vibralite modacrylic fiber, the finest quality synthetic fiber available. The collection is available in 21" long human hair and in four synthetic versions: long and mid-lengths in straight or softly waved textures. Affordable, lightweight and easy to attach, these virtually undetectable extensions can be put in and taken out in a matter of minutes.All HairDo Clip-in Extension Systems consist of one multi-level, contoured piece that creates an easy, fashionable style without the hassle of working with several individual wefts.