Abstract: An apparatus having a collet piece in a casing for attaching to a shock cord (or rubber or rubber composite cord or strap) anywhere along the length of the cord. The substantial change in width of a circular or flat shock cord as it is stretched is used to make the width of the cord narrow. When the cord is narrow it freely moves through a passage in the collet piece unit. When the cord is released to its fully relaxed width, the cord's width is wider than the greatest width of the passage through the collet piece and casing unit. The compression on the cord creates a frictional holding force between the collet piece, casing unit, and the shock cord. A tapered opening is provided in the casing so that when the cord is pulled in one direction while the casing is held, the frictional force causes the collet piece to slide along the tapered opening thereby reducing the width of the passage through the collet piece and casing unit to grip and hold the shock cord in the passage.