demo/src/app/components/+buttons/demos/checkbox/checkbox.html
<pre class="card card-block card-header">{{checkModel | json}}</pre>
<div class="btn-group">
<label class="btn btn-primary" [(ngModel)]="checkModel.left"
btnCheckbox tabindex="0" role="button">Left</label>
<label class="btn btn-primary" [(ngModel)]="checkModel.middle"
btnCheckbox tabindex="0" role="button">Middle</label>
<label class="btn btn-primary" [(ngModel)]="checkModel.right"
btnCheckbox tabindex="0" role="button">Right</label>
</div>