Shimano FC-M582 left crank bolt
Crank left arm fixing plastic bolt.
Crank arms compatibility:
FC-M800, FC-M780, FC-M785, FC-M770, FC-M771, FC-M760, FC-M761, FC-M660, FC-M665, FC-M590, FC-M591, FC-M582, FC-M583, FC-M545, FC-M533, FC-M532
To mount it properly, you can use the bottom bracket wrench Shimano TL-FC16 type.