Portable digital pianos, for the sake of lower production cost, were often equipped with a less complex system for the weighted keys. As a result, the feel of the keys is usually much less realistic than other digital pianos. However, it still retain the emulated weight mechanism (lower keys are heavier than higher ones), though not as precise as more expensive pianos, but far more true to life than a keyboard. However, certain models include synthetic ivory-like keys as opposed to standard plastic keys.