The solaraii is built with the same comfortable fit as our premium shoes thanks to a supple microfiber upper and a micro ratcheting low profile buckle that offers precise fit adjustment the upper is now welded and bonded resulting in fewer seams for reduced hot spots and improved comfort a supportive eva footbed with aegis174 anti microbial treatment is matched with our stiff dupont174 zytelnylon outsole to create an efficient powerful platform for transferring energy to the pedals