3M part number 3518 is aFour-Wall Header, 2500 Series is a .100” x .100” wire-to-board connector with a low-profile design that allows for design flexibility and space savings. A variety of versions and board mounting options makes the 3M header 2500 series excellent for a versatile range of applications. Its high-temperature insulator allows the header to be used for "no lead" soldering operations. A through-hole version is excellent for reflow soldering using "paste-in-hole" techniques. Center slot polarization makes insertion faster and helps prevent mis-insertions.