kksandr
--- a/src/Plugin/better_exposed_filters/filter/Select2.php
+++ b/src/Plugin/better_exposed_filters/filter/Select2.php
      '#description' => $this->t('Text to be shown in the Select2 field until a value is selected.'),
      '#default_value' => $this->configuration['advanced']['placeholder_text'],
    ];
+    $form['width'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Width'),
+      '#default_value' => $this->configuration['width'],
-      '#default_value' => $this->configuration['width'],
+      '#default_value' => $this->configuration['width'],
+      '#description' => $this->t('See possible values from <a href=":link">Select2 documentation page</a>', [':link' => 'https://select2.org/appearance#container-width']),