Variable Battery Power Supply, Holds Up To (4) D Cells - 1.5, 3, 4.5, Or 6 Volts Dc Power With 4Mm Sockets - Can Be Series Or Parallel, Perfect For Electronics, Physics, Or Even Biology Experiments
Dry Field Mapping Kit, includes cork-covered base, 30cmx26cm; pad of 25 sheets pre-printed conductive paper 28cmx21.5cm; pad of 100 sheets preprinted paper for drawing fields; ten metal-headed push pins; a silver conductive pen