Dynafit Ultra 100 GTX Trail Running Shoe was developed for all athletes striving to conquer ultra long distances.  Dynafit Ultra 100 GTX trail running shoe was developed for all athletes striving to conquer ultra long distances. The maximum volume of the Ultra 100 GTX trail running Shoe guarantees a comfortable fit even after hours of running on challenging trails. The cushioning needed for long runs was a key focus during the development of the Ultra 100 GTX midsole. Combined with a Pomoca outsole, ultrarunners get excellent cushioning and superb grip on all surfaces and conditions. With the Invisible Lacing system, a stretch lace cover adds increased protection and keeps dirt and pebbles from getting into shoes. Another feature of the Ultra 100 GTX is the Dynafit Heel Preloader Technology, a design element that improves heel fit. With all of this technology, plus a Gore-Tex Invisible Fit membrane, the Ultra 100 GTX is the perfect overall solution for your next, long trail adventure – no matter what the weather.