The 'Single view' plugin is placed on the page that will show the detailed view of products, if built-in view is not used.
All settings for this view can be found below the tab 'Single view options'. An option can be set to include a back-button (1) and it can show previous visited products (2).
If a product is unavailable, a message can be shown instead of sending the visitor to a 'Page not found' (404) page (3). The content of the message is set in the system configuration by a developer.
The last option on this tab, is regarding the image gallery of the product. The gallery is by default set to only show one image, with the option to cycle through all with navigation arrows (these show up by hovering the image). By checking the box 'Show gallery pagination' (4), all images will be visible, showing main image at the top and remaining listed below as thumbnails. (Img. 4.5.1)