evo.com | BCA Snow Study Tools > Avalanche professionals, serious ski tourists and Avy Level II and above students will need the durable BCA Aluminum Crystal Card as part of their ongoing study of the snowpack. 1 mm and 3 mm grids Aluminium Protective clear coat Snow grain classification "cheat sheets" 6 x 4" (15 x 10 cm) | BCA Aluminum Crystal Card 2026