My 02 4PT has a crappy light plastic rear view mirror and I can see fek all behind at any reasonable speed .
Any suggestions for a heavy ( to counter act vibration )rear view mirror . I have bark buster handle bar muffs so bar end aren’t going to work .
Thanks

Normal mirrors are heavier, probably unavailable, but M&P or demon tweeks would have various options for your choice, rectangle or round, black or chrome etc. the big single does shake the eyeballs a bit on “fast” long rides too. and the fillings out of your teeth.

Ive used these folding round mirrors on both my XT's and seemed to be fine, not excessively blurry at speed, although it is an XT, dont expect miracles. I think they fit the look of the bikes well and fold away for trail riding.

https://www.wemoto.com/parts/ab7862

Have a look at the Doubletake mirrors.
https://www.doubletakemirror.com/
I have the trail kit fitted to my 34L and they're better than the factory mirrors fitted to my 2019 KTM.

Thanks , Wemoto seem well priced , are they heavy enough to not respond to the vibration ?

They're not heavy, but theyre reasonable enough quality and not overly blurry at speed, I've done a lot of motorway miles on my 3aj and theyve been fine. I think maybe the hinged part, which is plastic with a bolt through it, will isolate the vibrations to some extent.

The brand, Vicma, make a lot of OEM mirrors for the likes of Yamaha, theyre not cheap knock offs.