This Hall effect based kit should be suitable for many applications. The combination can be used to measure magnetic field strength, for shaft encoders, to measure rotational speed (RPM), etc.
The kit includes 2 small rare earth (Neodymium) magnets. The sensing range for the pulse outputs with these magnets is around 2cm. A section of the PCB can be snapped off and wired to the main PCB for remote use.

Kit is supplied with PCB and on-board components.