COPPER SPRINGS Volume: 0.5 liters size of individual spring is  4mmx7mm Professional, bulk filling for columns.  It is used to maximize the heat exchange surface between the steam going from the canister to the dephlegmator and back.  Application: Before the first use and filling in new springs, they should be etched with 3% hydrogen peroxide with the addition of citric acid or washed in hot water with detergent and rinsed. The  springs Cooper and stainless selling separately.  You  need select which product do you want to buy.  

STAINLESS STEEL SPRINGS, ACID-RESISTANT FILLING Volume: 0.5 liter Professional, bulk filling for columns.  It is used to maximize the heat exchange surface between the steam going from the canister to the dephlegmator and back.  Application: Before the first use and filling in new springs, they should be etched with 3% hydrogen peroxide with the addition of citric acid or washed in hot water with detergent and rinsed.