in diameter to a generally maximum diameter at point b thereon the clamping portion 6 similarly is shown as being circular or round in shape but also may include other configurations such as polygonal and preferably includes a diameter or width of about 0 5 mm up to a maximum of about 5 mm alternatively the clamping portion 6 may present some variability in maximum diameter along its length the clamping portion 6 includes longitudinally arranged fibers 12 disposed outwardly of the core portion 4 in an exemplary embodiment the longitudinally arranged fibers 12 are originally part of the core portion 4 prior to treatment involving an air jet or brush this treatment opens the original tightly arranged fibers to create a fibrous portion outward of an untreated core portion 4 with fibers 12 having expanded volume interstices therebetween longitudinally arranged outward of the core portion 4 but still physically connected to the core portion 4 alternatively longitudinally arranged fibers 12 can be arranged over a section of the core portion 4 in a separate procedure for example as a sleeve not shown in this alternative embodiment it is preferred that some type of anchoring be effected between this outwardly applied sleeve of longitudinally arranged fibers 12 and the core portion 4 to minimize axially resiliency the remainder of the clamping portion 6 is comprised of a polymeric.