Unifiber HD C75 SDM mast range delivers a superb blend of durability and responsiveness that is optimal for many sailors.With their impressive performance, these masts are a great match for wavesailors, amateur racers and high-wind freeriders looking to step up their game. Flexes: We stock Constant Curve - if you would like to order Constant FL Curve or Constant FH Curve let us know HD C75 SDM mast range is introduced in three new specialized curves: Constant Curve — A 'classic' constant curve. Balanced and versatile, with the curve profile that has been preferred by many sailmakers for decades. Constant FL Curve — A modern-day flex top with a little more flexing in the centre. Constant FH Curve — Flexes in the top as much as the Green Curve but is a little stiffer in the centre, resulting in a very fluent curve. Please check out the Unifiber mast selector tool in the gallery to find out what mast curve works best for your rig. What is Universal Ferrule System? The new Unifiber Essentials masts all feature a Universal Ferrule System, meaning that all ferrules have the same dimensions, regardless of carbon content or curve profile. You benefit by being able to custom build your ideal mast with different tops and bases. For example, combine the strength of a 75% HD base with the light-weight performance of a 100% Elite top. Does NP use Flex Top? NP used Flex Top curves until 2016. Following years their mast geometry moved shifted closer to the Constant Curve. Our Constant Curve masts are definitely a very good match.