Mycoplasma cell membranes have how many layers

Mycoplasma cell membranes have Three layers.
Mycoplasmas (class Mollicutes) are the smallest and simplest self-replicating bacteria.
In Mycoplasma organisms the membrane seems to be composed of two electron-dense layers with a less dense layer in between this three-layered structure corresponds to the 'unit membrane' which covers cells and organelles of various origins.