This is a pair of genuine GM part number 10386222 that fits all SSRs 2003-2006. It is called an Auxiliary Spring (GM official name) or Bump Stop. It creates a soft stop for the fully compressed suspension travel.
These should be replaced in pairs only and that is what you are buying.
✅ When you place an order for “ONE”….. you will receive one PAIR of Bump Stops.