WordPress at a glance
filter is not described

customize_previewable_devices filter-hook . WP 4.5.0

Filters the available devices to allow previewing in the Customizer.

Usage

add_filter( 'customize_previewable_devices', 'filter_function_name_6807' );
function filter_function_name_6807( $devices ){
	// filter...

	return $devices;
}
$devices(array)
List of devices with labels and default setting.

Where the hook is called

WP_Customize_Manager::get_previewable_devices()
wp-includes/class-wp-customize-manager.php 4810
$devices = apply_filters( 'customize_previewable_devices', $devices );

Where the hook is used (in WP core)

Does not used.