3M DBI-SALA 50′ Sealed-Blok RSQ Single-Leg Self Retracting Lanyard With Galvanized Steel Wire Rope, Swivel Snap Hook, RSQ Dual-Mode, Anchorage Carabiner And 4′ Cable Tie-Off adapter. Sealed-Blok self retracting lifelines (SRL’s) incorporate a patented concept that separates all dynamic components, including the motor spring and brake, from foreign elements such as grease, moisture and dirt. You can always trust your SRL to work at peak efficiency without worrying about the environment you’re working in. Our sealed SRLs are backed by decades of proven field service for absolute confidence, safety and reliability. An SRL’s lifeline will extend as the user moves away, and retract automatically enabling the user to move about within a recommended working area at normal speeds. Should a fall occur, a speed sensing brake system will activate stopping the fall and reducing the forces imposed on the user to safe levels.