Target connectors are low profile

MILL-MAX Series 815 and 817 (single and double row respectively) low profile target connectors come with an above board height of 2.21mm. Devices are used in place of SMT pads on a pcb as the mating surface for spring-loaded pins. Products provide increased durability and are useful in achieving specific distances between boards. Devices are all surface mount, available in single or double row packages and are offered with flat or concave target faces. Concave face targets provide additional surface area for mating and can aid in centering/alignment of components and/or boards fitted with spring-loaded connectors.  http://www.mill-max.com