Really stupid question about the multidoes vial! But needs answer!

[Oxman]

Sorry for this very stupid question but I never used any AAS or injects of any form, but now that I opened the multidose vial (Dutch Lab Testonon 250), how to close it and store it? Please answer! I didnt think it was supposed to be left opened, but can't seem to be able to close it!

EDIT:
It's that black lid (i think lid is the correct word in english!), it won't fit...

 

[heavyiron]

If you removed the rubber stopper you are not supposed to. Rubber stoppers are meant to be pierced with a needle and the meds drawn out.

 

[dave 236]

If you're talking about the plastic piece that covers the vial when new, they break off and don't go back on.