How to retrieve image size in custom field array??

How to retrieve image size in custom field array??
I would like to get the medium or a custom image size not the full image.

there are any documentation for addon html attributes, item attributes, variables? ()

  {% for item in item.posts.cf_fotillo_array %}
<span> {{item.ID}} </span>
<span> {{item.id}} </span>
<span> {{item.title}} </span>
<span> {{item.filename}} </span>
<span> {{item.filesize}} </span>
<span> {{item.url}} </span>
<span> {{item.link}} </span>
<span> {{item.alt}} </span>
<span> {{item.author}} </span>
<span> {{item.description}} </span>
<span> {{item.caption}} </span>
<span> {{item.name}} </span>
<span> {{item.status}} </span>
<span> {{item.uploaded_to}} </span>
<span> {{item.date}} </span>
<span> {{item.modified}} </span>
<span> {{item.menu_order}} </span>
<span> {{item.mime_type}} </span>
<span> {{item.type}} </span>
<span> {{item.subtype}} </span>
<span> {{item.icon}} </span>
<span> {{item.width}} </span>
<span> {{item.height}} </span>
<span> {{item.sizes}} </span>
{% endfor %}