Amazon.com: SIM&NAT 12inch / 30cm 40 Pin Male to Female Dupont Wire, 40 Pin Male to Male, 40 Pin Female to Female Breadboard Jumper wire Ribbon Cables kit for Arduino Raspberry Pi 2 / 3 (120 PCS)
Amazon.com: ELEDIY 2 x 20(40 Pin) Stacking Header for Raspberry Pi A+/B+/Pi 2/Pi 3 Extra Tall Header (Pack of 4) : Electronics
Amazon.com: VSDISPLAY 40Pin to 40Pin ZIF 0.5mm Connector Adapter with Extension Flat Cable FFC Extend(200mm) : Electronics
Amazon.com: 2 x 20 (40 Pin) Extra Tall Female 0.1 Inch Pitch Stacking Header Compatible with Raspberry Pi A+/B+/Pi 2/Pi 3 Extra Tall Header (Pack of 8) : Electronics
Amazon.com: 40 pin connector
uxcell s16031200am0392 2.54mm Right Angle 40-Pin Male Pin Header Connector 100mm Length (Pack of 50): Amazon.com: Industrial & Scientific