Klim Nac PakThe Nac Pak from Klim is a medium sized backpack, perfect for those day trips that might turn into overnight stays. Versatile, the Nac Pak carries both your small or medium laptop and your tools. Slip in an optional bladder to stay hydrated. For those who dare the snow pack, the Klim Pak even has a place for an emergency shovel and probe (both sold separately).Features: Removable water-resistant tool pak External shovel and probe storage Large enough for small/medium sized laptops 3M Scotchlite reflective material Race-inspired shoulder straps integrates into sternum and side straps (no hip belt) Back panel is molded and vented Custom glove friendly zipper pullers Goggle chamois in molded goggle pocket Compression straps Emergency whistle Heavy duty nylon construction Internal organizer panel with key attachment clip Horizontal tool bag attachment Hydrapak 3 liter bladder compatible (sold separately) YKK heavy duty zippers