[No. 4]

[No. 2.5]

Extremely powerful 100% fluorocarbon Harris.
Strong, it is slightly inferior to nylon, but has excellent durability, scratches, and abrasion resistance, and is not absorbent (0%), so it will not degrade in water.
1.78 specific gravity for fast sinking (Nylon 1.14 / Ester 1.38), with a refractive index of 1.42, close to water 1.33 (Nylon 1.53 / Ester 1.60), so the line is not visible in the water.
The ultra-thin interlocking spool allows for compact storage.