More Pressure Mastering Compressor uses a technique called upward compression; it increases the level of quiet portions in a mix without reducing the level of attack transients like a traditional compressor.

It includes the 3 parameters found in its freeware sibling, Pressure Mastering Compressor - Amount of compression, look-ahead, and gain control - plus it adds a "Tweak" section with Ratio, Attack, Release, Threshold and Soften controls.