Soft Fluorcarbon,
 
The perfect material for those who love an 'IQ D-Rig' but also a great hook link to use for boom sections with Ronnie & Combi Rigs.
 
Fluorocarbon is well known for its high abrasion resistance, being fast sinking & virtually invisible on the lake bed. 
 
Supplied in 20lb breaking strain, 0.45mm diameter on 20 metre spools