- The RIO Powerflex Tippet Guide Spool is made from a a high tech co-polymer material, giving it excellent knot strength. A PTFE coating protects from abrasion, while giving it elongation (stretch) properties that average about 26%. Availabe from 7X to 0X, the Powerflex is perfect for all species. Its light grey color provides superb camouflage in the water. Most sizes- 110 yard spools. 0X and 1x- 75 yard spools.