Use the `placeholder` attribute to show a placeholder when no option is selected.

```html
<div class="max-w-[400px] h-[500px]">
  <sd-select size="lg" label="Label" placeholder="Placeholder example" placement="bottom" value="">
    <sd-option value="option-1">Option 1</sd-option>
    <sd-option value="option-2">Option 2</sd-option>
    <sd-option value="option-3">Option 3</sd-option>
    <sd-option value="option-4">Option 4</sd-option>
    <sd-option value="option-5">Option 5</sd-option>
  </sd-select>
</div>
```