The Brunton Grain Size Card is an essential field geology reference tool for the visual classification of sediments by size and shape. Lightweight and durable, this card can easily slide into a field pouch, vest, wallet, or pocket so it can be referenced whenever and wherever needed.

• Waterproof card can handle exposure to any type of weather
• Durable and lightweight
• Transparent card stock with both negative and positive sides for easier reading and comparing grain size in the field
• 10 grain size classifications including phi scale
• Grain shape reference
• Millimeter ruler