Without Glued-On Grains That Wear Off, Chart Stands up to Repeated use.

• Compare sediment sizes in the field or classroom

This translucent plastic comparator lets you quickly identify grain sizes; simply hold the comparator over the sample and match it to the graduated scale. The business-card-size chart includes millimeter scale, angularity chart, grain sizes in phi scale from -1.0 to +4.0; micron scale from 62–2,000; very coarse upper to very fine lower. Package of five.