A Class 1 SRL is generally intended for applications where the anchorage is at or above the worker’s dorsal D-ring and the lifeline is not exposed to a leading edge. A Class 2 SRL is designed and tested for more demanding anchorage configurations, including certain leading-edge applications and anchorage at or below the dorsal D-ring when permitted by the manufacturer. Class 2 is not automatically better; the correct class depends on anchor height, edge exposure, fall clearance, and the specific application.