Shimano FC-6800 left crank lock lockring, 20 mm

WARNING
For assistance with installation, adjustment and replacement of products which are not found in the user's manual, please contact 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 keep it in a safe place for later reference.
The following directions must be observed at all times in order to prevent personal injury, damage to equipment or damage to the surrounding area. The directions are classified according to the degree of danger or damage which may occur if the product is used incorrectly.
DANGER – Failure to follow the directions will result in death or serious injury.
WARNING – Failure to follow the directions could result in death or serious injury.
CAUTION – Failure to follow the directions could result in personal injury or physical damage to equipment and the surrounding area.

WARNING:
Do not disassemble or modify the product. This may cause the product to not operate correctly, and you may fall unexpectedly and be seriously injured.
Before riding the bicycle, check that the crank arms are not cracked. If there are any cracks, the crank arm may break and you may fall off the bicycle.
Be careful not to allow items of clothing to get caught in the chain during riding. If they do, you may fall off the bicycle.

CAUTION:
Be careful not to touch the teeth of the gears. There is a danger of injury.