Indian got my work(Z) type but it just have single entry and 0 days of duration ?

Hello, I am an Indian and i have applied for Chinese work Z and i got Z type but when i saw that visa and it says ENTRIES = 1 , DURATION OF EACH STAY = 000 DAYS AFTER ENTRY. It do not says anything about for how long (3 months, 6 months, 1 year) i can stay ? and it is just a single entry visa.
I want to know whats happening ? and whats Next ?