Mathias Kiwanuka Autographed New York Giants White XL Jersey 11975 This is a custom size XL white jersey with sewn on name and numbers that was personally autographed by New York Giants linebacker Mathias Kiwanuka. This jerseywas signed at the Collectors Showcase of America sports card show appearance in Edison, NJ on March 4, 2012 and includes a certificate of authenticity from Denver Autographs.