C,AA,AAA, D,N,9V 6F22 batteries and 1.55V button cell.Built of durable plastic and stainless steel.Usage: Fix a battery in the appopriate position and the tester will begin.The two measuring points of 9V battery are on the bottom of the unit.The battery's reading value will be shown on the LCD display in three areas: red zone-poor,yellow zone-weak and blue zone-good.