This 2x 20 Pin header socket is best used when plugging a shield on the ODROID-N2, such as the 3.5in. Touchscreen Shield. It makes your 40pin GPIO ports taller so you can access them easier, while the case protects your ODROID N2 from dust.
An example of the Header being installed on to the board is at the below. Note how the case is on the N2, and this header has raised the pin points out of the case, so you can attach the 3.5in. Touchscreen shield while still keeeping the board protected:-
A schematic is below:-
Odroid 2x20pin Female Header 
- Brand: Hard Kernel
- Product Code: 2x20 Pin Female Header
- Availability: In Stock
- Ex Tax: 2.50€