The ultimate elastic laces. We've tried them all. Your shoes will never feel better. What makes Xtenex unique to other laces are the bobbles. This allows for a different tension across different parts of the lacing area. Other elastic laces apply the same tension all the way through making them too tight in some place and too loose in others. But not with Xtenex. The Xtenex XH200 is for eyelet diameter sizes from 2.5 to 3.5 mm.