def get_size(vm_):
    '''
    Return the VM's size object
    '''
    vm_size = config.get_cloud_config_value(
        'fixed_instance_size', vm_, __opts__, default=None,
        search_global=False
    )
    sizes = avail_sizes()

    if not vm_size:
        size = next((item for item in sizes if item['name'] == 'S'), None)
        return size

    size = next((item for item in sizes if item['name'] == vm_size or item['id'] == vm_size), None)
    if size:
        return size

    raise SaltCloudNotFound(
        'The specified size, \'{0}\', could not be found.'.format(vm_size)
    )