So After having issues with quadkopter simonk 30 A esc's getting burnt(i was using 4s battery.maybe that might be a problem?)
i thought of using DYS 30A esc which are rated upto 16.8v .i couldn't find any source from which i can infer the reliability of these esc's . that's why i am asking community members if they can tell me if these are any good.
http://www.ebay.in/itm/301801635916?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
Also i couldn't find these or any god 4s rated esc's in any online hobby shop(except BlHeli ones on rchyper.com).

The seller describes the esc to have input voltage as 6~16.8V=2~4s
So I guess it is applicable for 4s
I have not heard about this esc so I don't know much. Please wait for someone who has used this esc
But this esc supports 4s

Eagely waiting for someone who had experience or know how about these

those esc are 2-5S capable.
I have used them with 3s and 4s, no issues.

Thanks sooraj.for giving me this little but important piece of information

This is the V2 . Please check if it is simonk or not.