Anti theft: built in 3 digit combination lock that protects your laptop, iPhone, iPad, and other valuables during traveling or standing in line. Simple to use, set and reset your own 3-digit combination in less than 30 seconds (please refer to video instructions) Maximum comfort: padded back and adjustable shoulder strap make carrying easy and helps alleviate pressure on your shoulder Multipurpose pockets: large main compartment is the perfect for your laptop, books, or journal. The external zip pocket provides quick access to your phone, keys, or boarding pass during travel or everyday use Water bottle pocket: This rucksack backpack has an exterior mesh pocket to conveniently carry your water, coffee, or sports drink, allowing you to be hands-free Versatile: This sling backpack is perfect for daily use to and from work or the gym. This stylish design comes in gray or Red and measures 9.75 in x 4 in x 18 in. Also available in a backpack/Daypack option