The silver futures trading unit of Shanghai Futures Exchange is 15 kg/lot, and the minimum change unit is 1 yuan/kg; The trading unit of a standard silver futures contract is15kg per lot, and the delivery unit is 30kg per warehouse receipt, and the delivery should be an integer multiple of each warehouse receipt. The delivery date is five consecutive working days after the last trading day, and the transaction must be made at maturity, otherwise the delivery will be forced.