This is a Mezzanine Connector Header Board-to-Board DF40 Series 40Pin 0.4mm Pitch SMT Gold Plated from Hirose Electric. This high-density space-saving design has a minimum connector width that still provides a sufficient vacuum area for easy pick-and-place mounting. This connector utilizes a locking system that prevents accidental unmating issues and emits a clear tactile click to ensure that mating has been completed. The shielded type can support high-speed signal transmissions with noise prevention. Both sides of the connector have been reinforced with the addition of shock-absorbing ribs and Nickel plated barriers were added to protect the contact areas from potential solder wicking.