Spectra is the registered trademark of Honeywell International for a special formulation of the same space-age material that bullet-proof vests and other tough protective gear is made from. Spectra is tiny filaments of super strong material that when braided together produce extremely strong, extremely thin line that is perfect for some fishing applications. Power Pro designed this Spectra line to feel smooth to the touch, which means this line won't cut your guides, and with less friction it will cast farther. It will also enhance knot performance and will lay better on the spool, which will also help increase casting distance. The near zero stretch of Spectra lines means you will have the ultimate in sensitivity so every twitch will be transmitted to your hand. Power Pro Spectra Line offers premium line at a reasonable price. Line Dia.8lb10lb15lb20lb30lb40lb50lb65lb80lb Inches.005.006.007.009.011.013.014.016.017 Millimeters.13.15.18.23.28.33.36.41.43 Equiv. Mono Diameter1lb2lb4lb6lb8lb10lb12lb16lb17lb