Dual use: (1) Approximate avalanche danger and (2) slope of terrain for hikers/skiers. Demarked with 3 levels of approximate avalanche danger (red, orange, yellow). Includes 1 mm, 2 mm and 3 mm grids for examining snow crystals. Grooved base aligns with ski pole or trekking pole for sighting. Compact size: Fits easily in pocket or clips to parka, pack or vest. Numerals and markings are engraved and paint-filled for maximum readability and durability. Temperature range: -40 degrees F to +125 degrees F. Instructions included. IMPORTANT NOTE: Avalanches can and do occur over a wide range of slope angles, and are influenced by several factors other than angular slope. Do not travel in avalanche areas without prior avalanche safety training, and always be alert to avalanche danger and travel accordingly.