Equipment and apparel

Federer currently plays with a customized Wilson (K) Factor (K)Six-One Tour 90 Racquet,[64] which is characterised by its smaller hitting surface (90 square inch),[64] heavy weight (12.5 oz strung weight),[64] and thin beam (18 mm).[64] Federer strings his racquets at a 53–60 pounds tension (depending on his opponent and surface), although at Wimbledon 2008 he was stringing at around 48 pounds with natural gut main strings (Wilson Natural Gut 16 String) and polyester cross strings (Luxilon Big Banger ALU Power Rough 16L String).[65] This allows him to hit balls at higher velocity with less effort but makes consistent accuracy more difficult.[citation needed] Federer also uses string savers to extend the life of the natural gut strings. Federer endorses Wilson tennis racquets and accessories and Nike footwear and apparel (he wears the Nike Air Vapor V and Nike Sphere Pinstripe Polo shirts).[66] For the 2006 championships at Wimbledon, Nike designed a jacket emblazoned with a crest of three tennis racquets symbolising the three Wimbledon Championships he had previously won. This jacket was updated in preparation for the 2007 Wimbledon Championships, with four racquets.[67] He also has endorsement deals from various other companies, many of them being Swiss.[68] He also endorses Gillette.[69]