Once you wear them, it is easier to understand why Nike retailers can never keep enough Nike Free 5.0 V4 in stock. Reappointed in synthetic microfiber with bonded seams to minimize chaffing, the Nike Free 5.0 V4 also included a new tongue design and a molded sockliner, all for runner's comfort. A system of cushioning, starting with foam inserts, Phylite midsole, the BRS1000 carbon rubber outsole, and finally a Nike Free sole with flex rating of 5.0, all dampen the impact when your feet hit the pavement. Plenty of support and shock absorption, no wonder this is one of Nike's best selling design. To be available at all Nike retail location in early April 2012.