The system is only as strong as what it hangs from.
Karabiners, screw links, textile slings and wire rope slings. The unglamorous end of the catalogue, and the end that fails first when it is specified by guesswork.
Karabiners and links
Screwgate HMS for belay and rigging, triple-action auto-locking for connections that must not be left open, and screw links for terminations that stay made.
Textile and wire slings
Sewn nylon tape slings rated to 22 kN, and TPU-jacketed galvanised wire slings for anchoring around structural steel and parapets that would cut textile.
Textile or wire
Use textile when
The anchor is smooth and radiused, the sling can be inspected before every use, and weight on the harness matters. Lighter, faster to rig, easier to inspect.
Use wire when
The anchor is sharp, abrasive, hot or unknown — structural steel edges, concrete parapets, pipework. A cut textile sling gives no warning.
Protect the rope regardless
Anchoring correctly does not protect the working line where it crosses the edge. That is what a rope protector is for.
Check the loading direction
A karabiner is rated along its major axis. Cross-loaded, a 35 kN connector is a 12 kN connector, and rigging that lets it rotate is rigging that will.
Not sure the anchor is rated?
Send a photograph and the structure detail. We will tell you what it will take and which sling to specify.