Oriental Pickled Fish in a Jar

I have a jar of fish sauce with what is apparently a length of pickled fish in the liquid.  This product was packed in Bangkok, Thailand and I think it is for Vietnamese but perhaps it is for Thai or Chinese cuisine.
 
The label reads:
 
Fish Sauce
Huong Vi Que Huong
Mam Lac
 
and there is a note "Premium Quality" and the contents are listed as "fish, sugar, and salt."
 
How is this product to be used?
 
Is only the liquid used and as a fish sauce?
 
If the fish is used it eaten a garnish over rice or noodles or as part of a sauce?  Or diced into a soup?
 
Is this Viet?  Are there similar Thai and Chinese products?
 
What is the shelf life?
 
Can someone refer me to an internet discussion of this type of product or recipes?
 
Thanks!