From Icebug.com:
Icebug is a Swedish footwear brand founded in 2001. We were frustrated by having to choose between the risk of slipping and saying no to our favorite outdoor activities. So we decided to challenge the global footwear giants and created shoes for running and walking on slippery surfaces. With a unique rubber compound that provides outstanding traction on wet surfaces and smart studs, which adapts to the surface and even grips on ice, we make shoes that allow you to stay active even when it’s slippery out there. Already, many people have experienced the safety and freedom that Icebug gives, but we have yet to reach many more!
BUGrip®
BUGrip® is the name of Icebug’s grip technology for the most slippery conditions. A BUGrip sole is made of a special rubber compound and has 15-19 integrated steel studs. The design of the studs, together with the properties of the rubber compound, give these studs a dynamic function. The studs work independently from each other and are not completely fixed. When weight is applied the studs push in toward the surface of the sole. How far they are pushed in depends on the pressure exerted by the user and the resistance from the ground. This dynamic function makes the studs adapt to the surface and provide the best possible traction on anything from dry asphalt to pure ice.