Adafruit Stacking Header for Raspberry Pi - 2x13 Extra Tall - 26-Pin GPIO
Stack multiple accessory plates on your Raspberry Pi using this splendid Adafruit header. It is described as "extra-tall and extra-long" this 2x13 female header becomes an important tool when working with the Raspberry Pi.
This product only works with Pi that have a 26-pin GPIO. I know "2x13" seems self explanatory but it's often better to make sure no one makes a mistake.
The spacing allows you to clear the ethernet and usb connectors. The header is 13.6mm tall: when installed on the Pi, The header pins are also extra-long, 9.7mm, so that when a standard 1.5mm thickness PCB is installed, there will be 8mm remaining, leaving enough room to stack something else.
Adafruit seems to have 32 of these in stock now I just checked. At one point I had a lot of 26-PIN GPIO accessories and this one was lying idle in a drawer and I will never use it so I am selling it. It is "new old stock" as they say.