DURABLE MATERIAL-This wire reducer is made of Brass with Nickel Plated and has good conductivity, acid resistance, and rust prevention, making it durable and long-lastingPACKAGE INCLUDE-The Power Ground Input Reducer Adapter package includes 4PCSconnectors, 4PCSspare screws, and 1PCHexagonal screwPRODUCT SIZE-The total length of the 4 Gauge to 8 Gauge Amp Input Reducer is 46.4mm/1.82inch, with a Screw ring wire diameter of 12mm/0.47inch and a top interface diameter of 5.4mm/0.21inch4GA TO 8GA-This is a 4 Gauge to 8 Gauge amplifier input reducer, suitable for most cars and can effectively improve the quality of sound transmissionEASY INSTALLATION-The installation of Power Ground Wire Reducer is simple, and it can be tightly connected by tightening the hexagonal screws included in the package