This is a pretty, well-constructed bag but when I received it it was bigger than I thought it would be - dimensions about 6.5"x5"x3". The top stays open well, the cord closure works easily and it'll fit plenty of chalk - but I'm pretty small and I have tiny hands, so if I probably should have done some my homework and found a smaller bag.
This was my second chalk bag and I love it! The adjustable strap is great. I have let others borrow my bag and they can adjust it to fit them without me having to undo my knots. I have found this bag flipped over in my duffel bag and it has not spilled chalk when it is scrunched up and stored. Overall a great bag!
Just bought some of my first climbing gear and I choose this for my chalk bag. Comes with a waiststrap so you can use that or clip it on your harness. It looks quite different than the pictures here though (looks better than the picture) Here's what mine looks like: http://i.imgur.com/V33gyu2.jpg