Vien,
Here is a very poor picture of one we carry. It is hard to see do to the white label in the back ground but hopefully this helps. It is 1/5-1/6 full. Enough to cover more than the bottom of the vial but it is not a lot. We sell several units a week and all have tested very well.
Please let me know if there is anything else we can do for you.
Thanks!
SRC