Guitar Tuner Standard Pitch 'A440Hz' And Why Some Tune Lower Than Standard? (Flat 'b' - Half Step Sign)

Guitar Tuner At A440Hz

On many guitar tuners, there is the A440Hz and we can change this to other Hz (eg. 438Hz) by pressing some button.

Always select the A440Hz - this is the widely accepted international standard ISO and concert pitch used by many countries. Read more here at A440Hz (Pitch Standard) (Wikipedia)

Guitar Tuner - Set At Default, Or Half-Step 'b' Or Whole Step 'bb' Lower?

If you accidentally pressed tuner and see the b/bb (flat or half step lower) sign - just continue to press, and select the default (without the 'b' flat sign).

But why do some guitarists want to set their open strings guitar tuning one half-step lower or even one whole step lower? (Note: one half-step is equivalent to one fret; one whole step to 2 frets)

They can be summed up here:- and also check out this thread Thread - Why Do Some Artists Tune Their Guitars Half A Step Or Whole Step Down?
(1) keep the tuning within the range of their voice
(2) create different music vibes eg. heavy metal
(3) easier to play with high action neck
(4) bend strings