NUX NAI-5 effects pedal dual acoustic guitar simulator OPTIMA AIRVerdugo Series NUX Optima Air is a dual switch acoustic guitar simulator with a preamp for acoustic and electric guitar players. It simulates the acoustic guitar profiles with the best optimized sound depending on your guitar and pickup type. IR loader combined with a preamp which is equipped with 3 band EQ and Gain controls. And there is an additional one knob control Reverb effect. If you want to connect any effect pedal you can use the SEND RETURN