The core of ROUNDTEN is Flextal®, a registered material in a high-carbon, titanium enriched austenitic stainless-steel alloy that offers great resistance to impact, pressure and rust. In addition, as indicated by numerous studies, this material has a hygiene standard far superior to plastic and 100% hypoallergenic. Different from our competitors, our high-carbon material offers higher adaptability, less fitting problems, particularly after few months of usage.
Hinge System
There are quite a few innovative hinges in the market. However, based on our own tests, our competitors’ hinges tend to break under regular pressure, due to weaker materials used, or are complicated to operate, or are prone to malfunctioning given any small deformation. The balance between innovation and performance is not always right. All in all, ROUNDTEN hinge system guarantees an easy-to-work-with product, long-lasting comfort, improved aesthetics and perfect fitting over time.
All Roundten sunglasses are equipped with polyamide lenses. Why Polyamide? Because it’s characteristics make the lenses almost unbreakable. So simple and so overwhelming. Thus, the eyes are always protected from any unexpected situation.It is hard to break a Roundten. Very hard! 

Another determining factor of the Polyamide is that they guarantee an extreme lightness, elasticity and a resistance against scratches never seen before. And they offer a high level of vision quality, infinitely superior to that offered by polycarbonate. So, the Polyamide is discovered as the best accomplice of Flextal. The complete formula of the materials that make a Roundten is not magical or secret like the Coca-Cola formula, but almost.