Preassembled 40-pin Pi Wedge Hookup Guide - SparkFun Learn
40 Pin GPIO Extension Cable for any 2x20 Pin Raspberry Pi [150mm / 6 long] : ID 4823 : $2.95 : Adafruit Industries, Unique & fun DIY electronics and kits
The Pi4J Project – Pin Numbering - Raspberry Pi 400
Adeept Raspberry Pi GPIO Breakout, T-Board + 830 Point Breadboard + 65 Jumper + 40 Pin Cable – Oz Robotics
Amazon.com: 40 PIN GPIO Header Adapter Color-Coded Header Expansion Board for Raspberry Pi 400,Easy Expansion : Electronics
reTerminal 40 pin connector keyed backwards - Raspberry Pi - Seeed Forum
Raspberry Pi Documentation - Raspberry Pi hardware
Raspberry Pi 40-pin GPIO 1 to 2 Extender – Geekworm
Powering StereoPi via 40 way GPIO Header - StereoPi Forum
Sintron] New 40-Pin GPIO Extension Board Starter Kit with RGB LED Swi – Sintron Technology
Micro Connectors For Raspberry Pi 40-pin GPIO 1 to 2 Expansion Board | eBay