Shimano 54mm cartridge brake shoes, pair
Shimano cartridge brake shoes, pair
These are Ultegra level 54mm length, aluminum, cartridge brake shoes that have toe-in adjustment built into the shoe. The black pads are not bad for wet and dry but when they wear out replace them with the better salmon yoko pad inserts.
Neat itty bitty bumpers are on the wheel guide/heat sink fins to prevent rim scraping and scratching when the pads are close to being all worn out.
Official Shimano name: BR-6700 R55C3