Shimano mounting screw for Octalink center

WARNING
For installation, adjustment and replacement information on products not found in the user's manual, please consult the place of purchase or a distributor. A dealer's manual intended for professional and experienced bicycle mechanics is available on our website (https://si.shimano.com).
For safety, be sure to read this “user's manual” thoroughly before use, follow it for correct use, and save it so that you can refer to it at any time.
The following instructions must always be followed in order to prevent personal injury and physical damage to equipment and the environment. The instructions are classified according to the degree of danger or damage that may occur if the product is used incorrectly.
DANGER - Failure to follow the instructions will result in death or serious injury.
WARNING - Failure to follow the instructions could result in death or serious injury.
CAUTION - Failure to follow the instructions could result in personal injury or physical damage to equipment and the environment.

WARNING:
Do not disassemble or modify the product. This may cause the product to malfunction, you may fall unexpectedly and be seriously injured.
Before riding your bicycle, check that the crank arms are not cracked. If there are cracks, the crank arm may break and you may fall off the bicycle.
Be careful not to get parts of your clothing caught in the chain while riding. Otherwise, you may fall off the bicycle.

CAUTION:
Be careful not to touch the teeth of the sprockets. There is a risk of injury.