The Fizik women's R4B Donna Boa Shoes are, essentially, a slightly less pro version of the R1B shoes turning cranks in the peloton for 2016. Like its pro tier counterpart, the R4B has a low cut ankle profile that allows for unrestricted pedaling motion and helps to trim some grams off the overall weight. Unlike the R1B, the R4B's outsole is a carbon injected nylon, and instead of a complete realization of the Volume Control system, the R4B features an asymmetric wrapping closure. The R4B's fastening system is built on a single Boa IP1 dial that pulls the upper across the foot, wrapping it rather than just cinching it down. This helps eliminate long ride discomfort by evenly distributing the pressure across the entire foot. While we won't be surprised to see this asymmetric design eventually appear across Fizik's shoe line, only the top tier R1B currently features a similar construction. The shoes are finished with two hook and loop straps across the metatarsals and toe box, allowing targeted volume in the areas that are prone to discomfort caused by restriction.