This is a 2x13 pin header with female socket (2.54mm pitch) on one end and male pins on the other end.

The female socket is 8.5mm tall and the pin part is 3mm tall. Overall, this header is 11.5mm tall.

It can be used specifically if you are making a custom add-on board for old Raspberry Pi Model A or B with 26 GPIO pins, not suitable for newer Pi boards with 40 pins.