An apparatus having a collet piece (41) in a casing (40) for attaching to a shock cord (43) anywhere along the length of the cord (43). The compression on the cord (43) creates a frictional holding force between the collet piece (41), casing (40), and the shock cord (43). A tapered opening is provided in the casing (40) so that when the cord (43) is pulled in one direction while the casing (40) is held, the frictional force causes the collet piece (41) to slide along the tapered opening thereby reducing the width of the passage through the collet piece (41) and casing (40) to grip and hold the shock cord (43) in the passage. The gripping width automatically follows the decreasing width of the shock cord (43) as it is stretched with increasing force.