Authorized reproduction of the users / instruction manual for a National Exp. B.T., sewing machine. It uses a vibrating shuttle and may have a motor. National bought the Eldredge sewing machine company and when the motor was added it was called the model Eldredge E. This machine had many badged names and was made for at least 30 years so this manual applies to a multitude of different machines. It has basic information about the machine, cleaning and oiling and some troubleshooting information. It also has extensive parts information in it.