This D battery holder accommodates 2 D-cell batteries and features 4mm banana plug terminals for easy connection to circuits and experimental apparatus. The base is made from folded sheet metal with spring-loaded connection terminals and secure battery snaps to hold the batteries firmly in place. The holder provides a convenient DC power supply alternative for constructing simple circuits in physics classrooms and laboratory settings. The RoHS-compliant 4mm banana plug sockets accept standard connecting leads and patch cords.