Chair-mounted seats in which the height of the sitting area can be adjusted must have locking mechanism(s) to secure the chair-mounted seat in its position of normal use.
Tooli külge kinnitatavatel reguleeritava istumiskõrgusega istmetel peab/peavad olema lukustusmehhanism/-mehhanismid, et fikseerida tooli külge kinnitatava istme asend selle tavapärasel kasutamisel.