Simple and sturdy, especially the strap and buckle.
Somehow, it's water-resistant and not water-proof; no internal zipper except for the small hidden pocket to store some loose change or a bunch of keys.
Would have been better if a small carabiner keychain is provided inside the bag and another strips of velcro on the front for better closure when the load is minimal.
[WHAT I STORE IN THERE?]
I'm not a messenger and don't ride a bike but I do carry a lot of tools and stuffs for my job as IT Engineers, and here is the list:
1 x 12" Laptop (in sleeves)
1 x 10m RJ45 cable
1 x 1m RJ45 cross-cable
1 x Network Cable Tester + Crimpers
1 x Screwdriver Sets (2 pieces)
1 x 101-key USB keyboard (full size)
1 x Optical Mouse USB
1 x Digital Camera (2.5" x 4" x 0.9")
1 x 5.25" External HDD (with HDD in there)
1 x 3.5" External HDD (with HDD as well)
1 x Gloves
1 x CD-Album (35 discs)
1 x A4 Sized Plastic File
1 x Magazine (not for the gun!!!)
2 x 1.5m 3-pin Power Cords
1 x Jansport Mobile Phone Holder (on the straps)
Talk about load, this messenger is a masochist; enjoyed being abuse. OK, I am no sadist but this bag is really cool!