Shimano BB UN300

From Shimano:

• A good quality bottom bracket for traditional chainsets
• Super-accurate bearings for smooth operation and improved durability
• Durable, hard-wearing sealed cartridge bottom bracket with square tapered spindle fitting
• Maintenance-free sealed cartridge bearing assembly keeps out dirt, mud, and water for long bearing life
• Fast and easy installation without adjustment
• Narrow body allows clearance for cable routing under the bottom bracket