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.
Cable is 6" long, and pin #1 is marked with a white wire.
This cable is not compatible with the Raspberry Pi Model A or B - It's for the A+ and B+ . Raspberry Pi 2 and Raspberry Pi 3 are also compatible with this product.
Pin #1 is marked with a white stripe.
• 173mm x 33mm / 6.8" x 1.3"
• Weight: 14.4g