Drupal 8: Form API - Weight Fields

Currently, I am working on a custom form that generates products on the fly for a custom purchase order implementation. 

For this Drupal 8 commerce website, the product variations have a required weight field which was needed in the custom form. 

Here is an example of the weight field.

    $form['product']['weight'] = array(
      '#type' => 'physical_measurement',
      '#title' => t('Weight'),
      '#measurement_type' => 'weight',
       //the default field is required and must be an array.
      '#default_value' => ['number' => 2.00, 'unit' => 'oz'], 
    );