Shimano Dura-Ace ST-R9270 Bleed Screw and O-Ring Ah, yes, the ever-important but often unheralded bleed screw. It keeps the air out and the brake fluid in, and lets you easily access the top of your hydraulic brake system during a bleed. Whether you've dropped and lost the original, or it's just time to replace it, never fear, the Shimano Dura-Ace ST-R9270 Bleed Screw and O-Ring is available to keep your brakes sealed off and working well. This screw comes with the bleed screw itself and a fresh rubber o-ring, which combine to seal off the hydraulic system from outside air and contamination. This bleed screw with o-ring is fully compatible with ST-R9270 Shimano Dura-Ace Di2 Brake/Shift Levers. Features Original quality replcacement is fully compatible with ST-R9270 Dura Ace Di2 levers Includes bleed screw and o-ring to properly seal off the top of the hydraulic braking system Shimano item number Y0MX98020 | Shimano | Dura-Ace St-R9270 Bleed Screw And O Ring Bleed Screw And O-Ring | Rubber