Oof - you got a Raspberry Pi 4 that you want to have work with some old kit or plate or breakout or something and it uses the classic 26-pinout. Very frustrating, it is...unless you have this ingenious 'downgrade' GPIO cable.
It has a 40-pin socket on one end, but only the first 26 pins have a cable and the other end matches any sort of Cobbler or PermaPi or what-have-you.
Cable is 6" long, and pin #1 is marked with a white wire.
Available in slimming Adafruit Black - pin #1 is marked with a white stripe!
Note: The Raspberry Pi Model A+, Raspberry Pi 2, Raspberry Pi 3, & Raspberry Pi 4 are also compatible with this product!
TECHNICAL DETAILS
Dimensions:
173mm x 33mm / 6.8" x 1.3"
Weight: 14.4g