Wordpress: Simple optionTree + Slick gallery

functions.php

// Add this in as $page_options_meta = array unde 'fields'

array(
                'label' => 'Insert Slider',
                'desc' => 'Select images to display in the header. Images must be 1200px wide by 410px deep.',
                'id' => $prefix . 'banner_slider',
                'type' => 'gallery'
            ),

WP-simple-slick-slider.php

<div class="image-banner">
        <?php $banner_slider = get_post_meta( $post->ID, 'tpa_banner_slider', true ); ?>
        
            <?php if (!empty($banner_slider)): ?>

                <?php $banner_slider = explode(",",$banner_slider);
                foreach ($banner_slider as $imageID) :?>
                    <?php $image_src = wp_get_attachment_image_src($imageID, 'full'); ?>
                    <div>
                        <img src="<?php echo $image_src[0];?>"/>
                    </div>
                <?php endforeach; ?>
            <?php endif; ?>
    </div>

Could tidy this up a bit. Maybe have a fallback if no slider is selected to featured image.