Each breakpoint has it’s own set of classes that can be used:

$breakpoints: (
  small: 0,
  medium: 640px,
  large: 1024px,
  xlarge: 1200px,
  xxlarge: 1440px,
);
<div class="hide-for-small"></div>
<div class="hide-for-large"></div>
...
<div class="show-for-medium"></div>
<div class="show-for-xlarge"></div>
...