These headers are great for soldering to your own PCB project to a Raspberry Pi 4 and stack on top with this normal-height female header with extra long pins.
The black plastic section is ~8.5mm tall, great for increasing the space between the Pi and your HAT/PCB for adding heatsinks (or just to increase clearance). It has long 10mm pins, allowing you to stack multiple HATs together.
We also stock an Extra-Tall version with additional spacers for additional height.
If you're looking for a stacking header to grip pass-through sockets (like the ones on the Fan Shim) you may want to check out our Extra Tall Push-fit Headers.