Every fly fisherman is looking for a slicker line, and for good reason. Slicker line means longer casts, which is something all anglers strive to achieve. XS Technology is the latest development from RIO's lab coats that focuses on creating an ultra slick line, with dirt-repelling tendencies. XS (Extreme Slickness) Technology began when RIO's chemists began reformulating conventional chemical combinations. Although RIO's formulas were great, our scientists are fly fishers, and by definition they want an even slicker fly line - it's just part of the deal. So first, they tackled the polyvinyl chloride (PVC) coating and through intense scrutiny down to the polymeric mix level, (say that 10 times fast) they defined some fundamental limitations. Out went the old PVC/silicone formulas and by methodically adding a little more of this, a little less of that, and a pinch of secret sauce, the lab coats cooked up a completely new and improved recipe. With XS Technology, RIO has developed a fly line that is slicker, more stable, and far less apt to attract dirt, and paired with AgentX Technology, it engineers a line that is less dense, casts further and more accurately, floats higher, lasts longer, and offers more consistent performance cast after cast, strike after strike, fish after fish.