Bbb rollerboys 12t sram narrow wide jockey wheels black

11t composite material provided by ems swiss with 40 glass fiber mixture complete set of bushings for different shifting systems included equipped with special internal lubricant system bearing type standard compatible with the following sram systems sram 9 0sl 2001 2002 9 0 2003 sram x 7 x 9 x 0 xx 2011 sram apex rival force red 2011 compatible with shimano made of grivory ems