4tronix-Initio-4WD-Robot-Platform-Inc-Motors-Gearboxes-&-Encoders-4tronix-Initio-p-The-b-Initio-b-is-an-easy-to-build-&-easy-to-use-4WD-robot-platform-designed-especially-for-use-with-the-b-Arduino-b-&-b-Raspberry-Pi-b-single-board-computers-This-extremely-flexible-platform-features-powerful-built-in-170-size-motors-with-high-quality-gearboxes-&-speed-encoders-on-each-side-Each-wheel-can-be-individually-decoupled-from-the-gearbox-so-you-can-run-the-robot-as-a-1WD-2W