The Duotone Whip SLS Concept Blue Kitesurf Board 2025... The Duotone Whip SLS, first time in Concept Blue construction, promises to revolutionize small wave and strapless freestyle riding. This cutting-edge surfboard boasts a revised shape and a range of features that will excite you on your first wave ever all the way to the world cup.. Available from H20 Sports with our Industry leading FIVE year warranty!