McDonald's Custom Burger is only available at certain outlets (11 of the bigger outlets spread across the island). You have to order using one of these self-service kiosks. You can choose what you want in the burger and even the portion size. I just went with one of the 3 pre-made custom burgers for a taste of McD vision.
My order number for a $12 meal, no upsize.
It's a really good burger, that tomato relish is TDF! I don't understand why they can't use real bacon, everywhere its turkey bacon.