Useful for the demonstration of characteristics associated with high voltage phenomena such as with Geissler tubes, spectrum analysis tubes .This induction coil capable of producing a spark with an requiring input of 4 to 12 V DC at 3 / 5 Amp and is therefore ideal for use with vacuum tubes, eudiometers etc. A fully adjustable vibrator system is incorporated and spark suppression capacitors are housed in the base. A pair of pointer electrodes  is  supplied  with the instrument. Pointer electrode has an insulating handle for adjustment of the spark gap. The Low voltage input is via a pair of mounted 4 mm Sockets Terminals are provided for H.T. output and L.T. input of the coil. Spark Length up-to 25mm at DC Input with 4 to 6 volt,3 Amp and for 50 mm  spark DC input 6 to 12 volt, 5 Amp is required