I purchased the Ultra bi-fold door set with white aluminium on the exterior and oak on the interior side. The doors look fabulous, the quality is superb and my builders found them a 'breeze' to install. Dealing with David from Vufold was a pleasure as they/he are always willing to answer any and as many questions as you may have. The only negative is the door set did not have a trickle vent option which gave me problems as Building Control require a fresh air source into the kitchen. Trickle vents are the easiest, cheapest and most common option. In the end I had remove a brick, replace it with an air brick and run ducting to ceiling vent to bring fresh air into the kitchen to satisfy building control.