Spare rubber band for Knog Blinder flashers, which have a replaceable rubber band-only clamp. You can also order a clip for the elastic band - code K11887.3 sizes.Short: For handlebars and seatposts 22 - 27 mm in diameter.Medium: For handlebars and seatposts 27 - 32 mm in diameter.Long: For handlebars and seatposts 32 mm in diameter and over.