GPIO Extension Easy Multiplexing Board for Raspberry Pi – 52Pi Store
Amazon.com: Mugast Extension Board Kit, GPIO Cable + Breadboard + GPIO T-Type Adapter Board 3 Extension DIY Kit Suitable for Raspberry Pi PI3 / PI2 / B + : Electronics
GPIO Extension Board for Raspberry Pi B+ 2B 3B | Makerfabs
Amazon.com: T-Type GPIO Extension Module Board Adapter with 40Pin Ribbon Flat Cable for Raspberry Pi 1B+/ 2B/ 3B : Electronics
Raspberry Pi 4 3b + Accessories T Gpio Expansion Board + Raspberry Pi 40p Data Cable Variety Of Options - Integrated Circuits - AliExpress
40-pin GPIO Extension Board for Raspberry Pi 2/B+ - RobotShop
Amazon.com: GeeekPi Raspberry Pi GPIO Extension Board, Raspberry Pi 4 Expansion Board GPIO 1 to 4 for Raspberry Pi 4B / 3B+ / 3B with Screws : Electronics
Cytron Maker Hat Base – HAT & GPIO Extension for Raspberry Pi 400 | Elektor
Inland RPi GPIO Breakout Expansion Kit for Raspberry Pi - T-Type Expansion Board + 400 Points Tie Points Solderless - Micro Center