Titanium Line Roller Upgrades for Shimano reels by MV Spools in Spain
 
These will last 10x longer than the rollers that come as standard, perfect for using with braid, Titanium is much more braid friendly and hard wearing, braid does has a tendancy of cutting through the line rollers over time.
 
 
These will fit most Shimano Big pit reels, such as the following:
 
Shimano Ultegra XTD
Ultegra XTB
Ultegra Ci4 XTC / XSC
Ultegra Ci4 XTB / XSB
Aero Technium MGS XTB / XSB
Aero Technium MGS XTC / XSC
Aero technium XSB / XTB / XSC
Aerlex Spod
Ultegara Spod
 
These are designed to slip over the already existing bearing / bushes, the only part you will have to remove is the line roller itself.