A beige ripstop rainproof waist bag from Porter Yoshida that can be turned into a backpack by undoing just one zip. With a total of 7 different compartments and the fact that this turns into a backpack means there is no shortage of space.
 
Condition: 9/10
 
Measurements:
waist bag width 13.5 inches
waist bag height 8 inches
total backpack height 19.5 inches