Product Description EPDM O-ring for Advanced seatposts by NEWMEN - a necessary component of your seatpost The prevents the loss of threaded inserts when removing the bolts during saddle assembly/disassembly. This makes the O-ring indispensable! If it is worn or damaged, you can find a suitable replacement here. Unscrew the bolts when installing/removing the saddle. Technical Information:Material:composite (EPDM)Size:28.6 x 2 mmCompatibility:Advanced seatposts Manufacturer Number:90113 Contents:1 x NEWMEN EPDM O-ring Manufacturer: MG-Components GmbH & Co. KG Am Mühlbach 5c 87487 Wiggensbach Germany info@mg-components.de