5 watt, 16 watt, 21 watt, ........
When ordinary Joe smashes his wing mirror and looks on line for a replacement, he invariably goes for the cheapest , me included. Then when it arrives and he opens the box , fits it, and it doesn't work he usually reverts to the Internet, me included.
And thank goodness for places like the Fiat Forum and all you knowledgeable contributors. I now know there are short,medium and long armed mirrors , heated and non heated, electric and non electric, temperature sensors and non sensor, dab aerial and non dab aerial and prices from £35.00 to £300 plus.
So if in any doubt take the old one off and check it over before buying a replacement and yes definitely ask the vendor, me included.......