The headphones and amplifier have been tested and confirmed to produce sound using batteries and a power adapter. There is no noise or crackling that would interfere with playing. Please check the photos for the condition of the item, as it is a used product. The set includes everything shown in the photos (including the stand). The neck is not warped. There is plenty of fret life remaining. The truss rod has not been checked. The string height is slightly high, but this is within the range that can be adjusted with the nut, not due to neck warping. The seller has not used the item themselves, so the frequency of use is unknown. Please adjust the pitch and string height to your preference. As the item has been confirmed to produce sound, we guarantee returns up to the point of confirmation of receipt in the event of any defects, such as no sound. Please understand that there may be some scratches or minor, inconspicuous marks due to the item being used. The item will be carefully packed with bubble wrap and cardboard for shipping. In accordance with Yamato Transport's recommendations, the strings may be slightly loosened for shipping. YAMAHA Silent Guitar Operation confirmed, Red