What is the difference between an SRL, SRD, and PFL?

A self-retracting device, or SRD, is the broad term for equipment that automatically extends, retracts, and locks during a fall. A self-retracting lifeline, or SRL, is a common type of SRD. A personal fall limiter, or PFL, is generally a compact SRD designed for shorter working distances and direct attachment to a full-body harness. Confirm the approved use from the product label and manufacturer instructions.