This part will improve performance for road cyclists, by allowing a bigger rear cassette installation. Bolt included. Works with any 1-11 or 1-10 Drivetrain (42t max cassette, with a single chain ring crankset). Crank should be with a single chain ring or a double chain ring where the difference between the plates sizes is 14t max (with an exception: works with a compact Shimano crank of 34-50t plates, 2-10 cassette 11-36t). In a double chain ring crankset there is a limitation of 40t rear cassette with Shimano and SRAM, and 36t with Campagnolo.