How does 3M 425 compare to 3M 3340? 3340 is some foil tape I bought from Lowes in the HVAC section, with "cold weather" printed on it in red text.
In terms of thickness, I see 425 is 2.8 mils thick, vs 3340 which is 2.0 mils.
In terms of temp range, I see 425 goes down a bit colder (-65 F vs -40 F).
They seem really similar, like 425 is a somewhat improved version. But it's surprising that this comparison PDF, which shows a lot of 425 alternatives, doesn't show the basic stuff I got from Lowes (3340) https://multimedia.3m.com/mws/media/1390627O/3m-aluminum-foi...