@Min-Liang Tan After using the pack, I have noticed a few things that would improve it pretty considerably. The thing that stands out to me most as a flaw is the fact that there is now zippered pocket on the top flap. I am a backpacker, and those pockets make it super easy to keep track of things like sunglasses and keys. Adding a pocket to the top flap would be a great way to improve the functionality. It would be a neat idea to make the headphone mount/case compatible with the MOLLE on the outside. I carry books and notebooks, so being able to carry taller items in the main compartment is important. The headphone mount blocks those, so I cannot actually carry it with me when I am at school. The lower side Velcro straps can slip through the MOLLE on the pouch to lock it closed. Not a flaw, just a cool feature. I managed to strap a keyboard ( Not Razer, I know. Next purchase ) to the side of my pack via the Velcro, with the bottom half fitting into the wide side pocket. Other than those things, this pack is really solid. Super comfortable, Sexy, and it feels Bulletproof. Great job.