{{#slds-control-identity as |formElementId|}}
  <span class="slds-button slds-checkbox_button">
    <input type="checkbox" id={{formElementId}} disabled={{isDisabled}} onclick={{checked}}>
    <label class="slds-checkbox_button__label" for={{formElementId}}>
      <span class="slds-checkbox_faux">{{label}}</span>
    </label>
  </span>
{{/slds-control-identity}}