I purchased this product less than a year ago. I have stored it in my car since that time in case of an emergency. However, on two occasions of a dead battery, this cable has failed me. With further investigation, I have discovered that this cable is faulty. It cannot jump a car, where other cables can. It does not even spark when two live leads are touched together. It simply cannot conduct electricity. This cable did not suffer from damage or improper use. It was stored safely away in case of an emergency. This is a manufacturing defect. This cable has resulted in many hours of wasted time. DO NOT RELY ON THESE CABLES IN AN EMERGENCY!
-Update - Customer service was very understanding and sent me two new cables to replace my broken one. I appreciate that they were understanding and accommodating!