4mm Rope cable locks. Used for securing 3.2mm Marine Stainless 7×7 cable to anchors and to poles.
These are to hold up a section of cable to your poles for 5-50 plants. We use these same locks on our dwarf system here with 20m rows 4m high with 3 at each end.
6 at a time because each cable needs 3 per end. Remember never saddle a dead horse!