El Paso, Texas-based RWC Testing & Lab Supplies has begun offering a series of optical hand-held refractometers to measure soluble solids, or Brix content, in fruits and vegetables.

A focusable eyepiece with a high-contrast scale system provides users with easy-to-read results, according to a news release.

Each unit comes with a rubber sleeve to cover the instrument body and protect the sample solution from body heat, which could compromise the accuracy of readings.

At 7.5 inches and 10 ounces, the models are portable.