A heavy duty, two cell counter. It records up to 999 for each cell. It also has a totalizer that show the sum of all two counters. Internal bell sounds at one hundred increments of the total count. The reset knobs on both sides can clear all the numbers to zero. Has red and white keys for better visibility and reducing mistakes. Specifications:Weight: 360 grams Length: 18 cm Width: 8 cm Height: 5.2 cm When recording, use one key at a time Two keys denoting LYMPH, POLY, and a totalizer window labeled TOTAL.Each key can record up to 999 Corrosion resistant outer ABS shell.Zero reset knob on either side. At increments of 100 totalizer unit rings a bell.To count properly you must fully depress one button at a time. You must also test and calibrate the counter upon arrival if needed