<div id='container'></div>

var WithLink = React.createClass({
  mixins: [React.addons.LinkedStateMixin],
  getInitialState: function() {
    return {expanded: false};
  },
  render: function() {
    var details = <p>Detailed description of the product</p>
    
    return (
      <div>      	
  			<input type="checkbox" id="c-details" checkedLink={this.linkState('expanded')} />
			  <label for="c-details">Show Details</label>
  			{ this.state.expanded ? details : false }
	 	 </div>
  	);
  }
});

React.render(<WithLink />, document.getElementById('container'));