You put the headers on top of your Arduino and then you can add shields like our Protoshield or our Motor Shield or our ProtoScrewshield (pictured above) to get your Arduino doing all the cool things you want it to. Our set includes 1x 10pin header 2x 8pin headers 2x 6pin headers and one 2×3 header.

The legs are all 10.5mm long so after PCB thickness (1.7mm) you have a height of 8.8mm just enough to clear the Arduino’s USBB connector. They?re also fully compatible with shields designed for Arduino R3 and the Leonardo. For shields that don?t use the 10pin header or 2×3 header use the 6 or 8 pin ones.

Some experimentation might be necessary to get these working. For example:

You can stack on top of a Proto Shield but not if there is a breadboard on it
You can stack on top of an Adafruit Motor Shield v2
You can stack on top of a Wave NFC/RFID or GPS shield with no problems
You can stack on top of an Ethernet shield but you’ll need two sets of headers to clear the Ethernet jack.
You can’t stack on top of our TFT or LCD shields
Some shields use the ICSP (2×3) header in which case you may need to solder in the stacking 2×3

Really the possibilities are endless just keep in mind that you may need to do some adjusting of code to handle the multiple devices and that there may be pin compatibilities.