Samsung Gear S3 classic User Manual page 24

Set a Screen Lock
Prevent others from accessing your Gear when you are
not wearing it.
If you set the screen lock feature, the Gear requires an
unlock code whenever unlocking it.
PIN
► On the Apps screen, rotate the bezel to
> Security > Screen lock > Screen lock type > PIN.
•
A PIN consists of numbers only. Enter four
numbers, and then enter the PIN again to
verify it.
Unlock the Gear
► Turn on the screen and enter the unlock code.
Getting Started
Settings
15 Set Up Your Gear