Runners looking for a smooth ride from start to finish will experience a spring-loaded ride with plush underfoot comfort in the GEL-Flux™ 4 shoe – thanks to the Guidance Trusstic System® Technology. The breathable mesh underlays provide a sock-like fit, designed to increase air-flow and maintain comfort when the conditions heat up. Weight: 12.4 oz. Heel Height: 23mm. Forefoot Height: 13mm.