10N Newton Force Meter Spring Scale Dynamometer for Physics Mechanical Experiments, Green, Plastic and Iron, 6.1 Inch

This is a common item. Most see this as it is a cheap spring gauge. The scale repositions to account for spring wear and inaccuracy. This is handy for setting thread tension on sewing machines. Use an expensive gauge to see where you're at and then keep this with the machine so you don't have to break out all that other stuff from the tool box. 6 bucks.

The package was destroyed and looked like it was taped back together. The weight was not calibrated. There was a piece of animal hair on it and there was debris/dirt inside the package. The weight itself looked well used, too.

I used this as part of a rig to measure the closeness of a 3D printer nozzle to its bed, and it worked perfectly. The firmware was buggy and didn’t properly build the mesh, so I had to manually build it. It feels as though it could lose accuracy over time, but for immediate comparisons, it’s a cost effective solution. It’s good for a science project, but I wouldn’t use it to measure newtons on a corporate job.

It worked in my granddaughter's experiment.