When I received the bass, it appeared that the truss rod nut was stripped. I contacted the seller who was unaware of the issue because he had never adjusted the neck. Long story short, we came to an agreement and he refunded my money and I shipped the bass back! Very stand up, ethical move on his part. This was a tough situation for both of us, because we both understood the others position. I do hope the owner that sold him the bass was as ethical and was not aware of the issue also. Seller informed me that after receiving the bass back that a 4mm hex allen wrench appeared to function properly....