SS4 series ultra fine 0.4mm pitch, board to board low profile dual row socket strips with a PCB space saving slim body design. The insulator of these SMT ultra fine 0.4mm pitch, low profile socket strips is made from black LCP and the Razor Beam ™ contacts, which are ideal for high speed and rugged applications, are made from phosphor bronze with a 0.25μm gold plating on the contact area and a matte tin plating on the tail. These SS4 series high speed SMT board-to-board low profile socket strips have a 1mm contact swipe and are polarized as standard with undercut retention notches that click when the contacts engage and increase withdrawal force.
Part numbers SS4-xx-3.00-x-x-x-xx have an above board height of 3.50mm.
Part numbers SS4-xx-3.50-x-x-x-xx have an above board height of 4.00mm.

0.4mm Board-to-Board Headers and Sockets - Samtec