You have to clarify if it was a true secondary spring or just a helper or tender. Helper or tender usually is 5" or less long and sometimes has flat spring material. These are primarily used when you find a ride height you like but the spring goes loose at full droop. So it just keeps tension on the main spring when you're in the air. Unless you're going really fast in a big truck, you can usually do your homework and avoid using one since it really does nothing for us land lovers.