Bonding wire material: special copper, with excellent conductivity, different from the aluminum usually used indoors, which makes this product unique. DuPont cables include: 1x40 male to female, 1x40 male to male and 1x40 female to female.It is also suitable for industrial/professional applications as our copper blends have extremely high durability. Cable Length: Each cable measures approximately 20cm with 2.54mm spacing.Each harness consists of 40 individual wires, which can be easily separated from each other and firmly fixed in your socket or pin during use. This DuPont cable kit is suitable for various applications. With our cables you can easily and reliably connect all modules to the Raspberry Pi breadboard or GPIO on the Arduino. The quality is very good and there is no plastic smell.Circuit testing can be done quickly without soldering.If the terminal is not damaged, it can be reused.