array(
    'type'  => 'slider',
    'value' => 33,
    'properties' => array(
        /*
        'min' => 0,
        'max' => 100,
        'step' => 1, // Set slider step. Always > 0. Could be fractional.
        */
    ),
    'attr'  => array( 'class' => 'custom-class', 'data-foo' => 'bar' ),
    'label' => __('Label', '{domain}'),
    'desc'  => __('Description', '{domain}'),
    'help'  => __('Help tip', '{domain}'),
)