LG WFS1739EKD Owner's Manual page 36

Soft Safety Door
Using tempered glass, inside can be seen while washing and safety is guaranteed.
To prevent sudden close of door, it uses smart hinge so the door closes softly.
Door is heavy. Be careful not to be caught in hand or other material.
It might cause injury or damage on product.
Smart Hinge
NOTE
• For customer safety, the door will be locked automatically during operation (Light turn on "door lock" )sign.
If there are additional laundry to put in, press operate/pause to unlock.
• Press START/PAUSE Button again to resume operation.
36
Smart Hinge