Torx chainring fixing bolts are the front Torx T30 chainring fixing 'bolts'. Chainring fixing nuts are 'nuts' that require the use of a chainring nut wrench. Torx hidden chainring fixing bolts are the Torx T30 hidden fifth chainring bolt that thread directly into the crank arm. The 11 and 10 speed model fitment includes: 11 speed Super Record, Record, Chorus and 10 speed Record and Chorus. Sold individually