The spreader bar is made of steel with pressed loops at the ends.
If necessary, attach the stick to the centerline with cable ties, etc. or with a rubber band / o-ring.
When buying a complete spreader, it comes with 35 cm ropes in 4 mm D-Pro or 3/4 mm plastic wire with loops at both ends. You can attach it to the center line with a soft shackle or with your own solution.
When ordering tuglines, you order 35 cm shorter than usual. (ex. team normally 1200 mm with spreader 850 mm)
Only the spreader stick can be used with your regular PE or D-Pro tuglines as well.