That's a good question. There are two types of cages for Nintendo games. The type that uses screws to secure the filterboard door (i.e. Popeye, Mario Bros., Donkey Kong 3) and the type that uses plastic pushbuttons to secure the filterboard door (i.e. PlayChoice Single/Dual Monitor Cabs and VS Unisystem/DulaSystem Uprights). Both cages will hold the PCBs the same and the dimensions are the same...only if you get the wrong type you won't be able to secure the door.