Some people believe in twice a week or even EOD injections with sust, yet others argue that it acts like a single ester test. So, choose a side, or just experiment by running one cycle one way and the next the other.
It depends who made it etc etc, there are 1ml/5ml/10ml/50ml. The 1ml stuff comes in glass containers that you break the top off of to get your stuff. Everything else should come in a rubber topped vial.