The cutter or grinder could fall out and cause injury.
Pull on the cutter or grinder to check that the chucking system is okay and the cutter or grinder is securely held. When checking, inserting and removing,
use gloves or a fingerstall to prevent an injury or infection
Rotate the clamping ring all the way in the direction of the arrow, and insert the handpiece cutter or grinder into the chuck.
Turn the clamping ring into the initial position.
Check that the cutter or grinder is seated by pulling on it.