Brake Pad Wear Indicator
That’s not a pig pen in your glove compartment. Many cars have an indicator that will squeal when pads may need to be replaced.
What is the brake pads minimum thickness?
Are your brakes squeaking or grinding?
Does the brake pedal feel soft or fade? Do your brakes pull or pulsate?
Is the brake light or ABS light is on?
Has it been 12 months or 12,000 miles since you’ve had your brakes checked?