The Hard Core Brands 02-300-0022 snap-back jerk string is used when the wind and water aren't working to give your spread the natural movement you need, you have to take matters into your own hands. Literally. The hard core snap back jerk string is the perfect tool for giving you something to shoot at on the calmest days. With your decoys attached to the string, all you have to do is give a gentle tug to create natural, bird-attracting movement.