BenQ DW1620-exact model

Hi I’m in the UK -looking at this drive

Whatis the exact model? -I’ve read about a,b,Pro spec.-any ideas what this is likely to be?

Will I be able to upgrade to 4x DVD+R DL?

The 1620 & 1620 Pro are the same drive from the firmware B7P9 onwards BenQ introduced new features to the drive and created the 1620 Pro brandname as a means of marketing said features.

Any 1620 flashed with B7P9 or later firmware becomes a 1620 Pro and yes you will be able to burn DVD+R DL at 4x but only Verbatim discs.

So as this is a retail version I’d be looking to use firmware B7U9 ?

Correct though people have had mixed results with B7U9 and some prefer B7T9 I’d suggest try T9 first & then once comfortable try U9 and see how it goes because the tweaked WOPC algorithm in U9 prevents burning Verbatim DVD+R DL at 4x for me at least but they burn at 4x with T9 just fine.