This is a 2x20 specialty header with male pins (2.54mm pitch). Overall, this header is 15mm tall with 6mm tall for the pins on both end and 3mm tall for the plastic spacer in the middle. What so special about this header is when paired with a 2x20 female connector, it becomes a gender changer.

This header can be used with a ribbon cable to effectively turn it into an extender GPIO cable for a Pi HAT.