SS4/ST4 series narrow body, super fine pitch low-profile board-level interconnects have a 4 mm wide socket strip and 5 mm wide terminal strip, with 0.4 mm pitch. Standard mated stack height is a low profile 4 mm from board-to-board with a choice of applications specific heights from 4.5 mm to 6 mm. Available with up to 40 positions per row in a double row design and rated at 7 GHz in single-ended and 4.5 GHz in differential pair configurations when mated.
Samtec, www.samtec.com