The BCA Aluminium Crystal Card is a versatile and informational card that will take up barely any space. For studying snow crystals and slope angles in the backcountry. The aluminium crystal card provides a surface to analyse/classify snow grains and also has a slope index, which allows you to determine slope angles from a topographical map. Snow crystals placed on the card become recognisable and sizable. With the aluminium card version, you can expect durability and long term usage. This small yet very informational tool will take your snow safety skills to a new level.