The Provision has proven itself, and with this updated version comes plenty of updated features. Simplified mesh construction and an improved heel provide a better locked-in feel. The refined InnovArch™ feature offers a more tailored fit and encourages a more natural step cycle. The GuideRail™ brings additional medial support that"s only there when it"s needed. The Provision 5 is comfortable, supportive, and ready for your long runs.