Flurocarbon. Tops for traces, purely for presentation of your bait as it tangles less around your mainline, and is substantially more abrasion resistant than standard mono. Be very careful in pulling knots up tight. Slow is the key, lubricate {Spit} and few turns, 3 or 4 in a blood knot. Alternatively, CRIMP. I prefer Stren Coral mist in 50lb and can crimp this with .7mm ali crimps thru and back.