What is This Varistor?

Probably is a varistor (MOV), but could possibly be filter. A quick internet check didn't bring it up (but the component number looks familiar).

http://www.littelfuse.com/products.html

Are you sure it's 220Vac and not 120Vac (that would explain the 185V?? rating)?

Check the circuit to ascertain the components function, if it is a MOV just replace with something of similar voltage rating and physical size (which dictates the devices energy handling capacity).

i am sorry it is on 12Vdc input

What exactly is the circuit, it may help identify the part function?

Are you sure it is in parallel and not in series?

Does it have two leads or three (with the third conected to ground)?

it is series not parallel an it is two leads

Well it's not a MOV then. It is probably a polymeric positive temperature coefficient (PPTC) device, commonly called a "Polyswitch". They have the same distinctive package as MOVs and are commonly used as a self-resetting fuse for audio and other electronic circuits.

http://en.wikipedia.org/wiki/Resettable_fuse

http://www.google.co.nz/search?hl=en&source=hp&q=polyswitch&meta=&aq=f&oq=