Datasheet

against stuff.
Next we will place the two
1.0Kohm resistors. These
resistors are used to set the
brightness of the LEDs. If you
want brighter LEDs you can
substitute 220 ohm resistors. If
you want dimmer LEDs, you can
use 4.7Kohm.
Resistors do not have 'direction'
so they can go either way and
work fine. Place the two resistors
into the silkscreen slots on the
right of the PCB.
© Adafruit Industries https://learn.adafruit.com/adafruit-proto-screw-shield Page 22 of 24