Kibeland Handheld Clinical Refractometer, Serum Protein 0~12g/dl, Urine Specific Gravity 1.000~1.050sg, Refractive Index 1.333~1.360 RI, with EXTRA Mini USB Light

A family member needs to be able to monitor urine specific gravity. I'm a physician, and I know refractometers can be expensive. This is a great value, it's as easy to read as the expensive ones, and comes with a nice case with instructions, several squeeze-bulb pipettes for sampling whatever you're sampling, and a cleaning cloth. It seems sturdy enough, and was easy to calibrate.

Perfect for reading specific gravity of urine.