3D Printer Extruder Bearing
V624ZZ Ball Bearing 1 piece
You can diy your own fishing line pulley for a delta robot 3d printer like Rostock. Besides that RobotDigg recommend you a V type bearing V624ZZ for your Rostock as pulley of the fishing line.
U604ZZ Ball Bearing 1 piece 4*13*4, U2*1
U604ZZ is option of V624ZZ in kind of 3D Printer Extruder construction.