NSK S-Max pico Mode D'emploi page 11

5. Replacing the O-rings ( pico )
Replace the O-Rings if water is present in the exhaust air line. This is an indication of possible water leakage within the coupling.
ALWAYS change the complete set of O-Rings.
1 ) Loosen and Remove the Taper Ring at the rear of the handpiece. ( Fig. 7 )
2 ) Gently remove each O-Rings with your thumb. ( Fig. 8 )
3 ) Insert the complete set of new O-Rings in the correct grooves.
4 ) Replace and firmly tighten the Taper Ring.
PTL O-ring Set:
Order Code Y900580
Loosen
Taper Ring
Fig. 7
O-Ring
Fig. 8
9