The polyester cord is a continuous string of “buttonholes” that can be threaded in and around various loom parts and secured with either of two styles of pegs: straight pegs or anchor pegs.
Most people only require the thin u-cord (1/12) because it has a breaking strength of 80kg! Option one yet thinner u-cord (1/12 3 thread).
For the heavy loads of counterweight rollers or warp beam aprons you may prefer the thicker cord (1/20).