BRASSELER USA NL4500 Operation Manual page 8

5. Insertion and Removal of the Bur
5-1 To Insert the Bur
1) Insert the bur until it is correctly seated in place. (Fig. 3)
2) Depress the Push Button and insert the bur into the chuck until it
is secure then release the button.
3) Ensure that the bur is secure by gently pulling and
pushing the bur WITHOUT depressing the Push Button.
5-2 To Remove the Bur
Depress the Push Button firmly and remove the bur.
Fig. 3