https://www.14point7.com/products/sigma-lambda-controller-free-2

This controller works with genuine Bosch LSU 4.9 wide-band oxygen sensor. Allows you to, for example, fine tune a carburetor or verify your engine operation. Very useful, simple and accurate.

In a set with sensor cable and supply cable, however you may find those cables too short - I can provide longer cables at extra cost.