The Brunton Grain Size Card is an essential field reference tool for the visual classification of sediments by grain size and shape. Made from transparent, lightweight and durable plastic, it fits easily into a pocket, wallet, vest or field pouch and can handle exposure to any kind of weather.

The card provides 10 grain-size classes including the phi scale, a grain-shape reference and an integrated millimeter ruler. Positive and negative sides make it easier to compare sediment samples directly against the printed patterns in the field.

Dimensions: 2.5 × 3.675 × 0.06 in | 6.35 × 9.33 × 0.2 cm
Weight: 0.2 oz | 6 g