The ANC-Mini makes the audio from your Spirit Box amplified by reducing noise distortion. This produces a cleaner clearer audio that makes it easier for the investigator to notice and decipher EVPs. It works with all Spirit/Ghost Boxes that has an audio output. For example: SB7, SB7T, SB11 Spirit Boxes, Para4ce Ghost Box, S-Box. It uses a unique software algorithm that automatically adjusts the Audio “Hold & Release” settings. It is extremely easy to use the ANC-Mini. It uses only 2 control buttons. Comes with: 2 Audio Cords, 2 AA Alkaline Batteries, 1 Velcro so you can attach it to your Spirit Box. Warranty: 1 Year from Manufacturer. NOTE The ANC-Mini must be connected to a speaker through a 3.5 mm audio input port (AUX) for any audio to be heard. It does not have Bluetooth. NOTE regarding use with SB11 SPIRIT BOX: You can only use one channel at the time through the ANC Mini since it does not have two input ports to connect both AM and FM simultaneously from the SB11.