Detachable swan neck towbar, where the neck of the towbar can be removed when not in use.
Detachable towbars avoid any issues with parking sensors picking up the tow bar neck, so ultimately if your car has reverse parking sensors this would be the best option for you.
The flangeball towbar is a commonly used type of towbar in this country.
On this type of towbar, the towball is bolted on to a faceplate on the tow bar, this allows accessories such as bumper guards and cycle carriers to be bolted behind the towball.