Especially following renovations a few years ago, Lambeau Field offers a number of indoor seating options. The seller of these tickets decided to add the note about "open air" seating - though typically it is assumed that seats will be outdoors and notes are usually added for "indoor" seating. All 100-level seats are exposed to the elements of the Frozen Tundra.
The seats in Section 446S are a part of the South Endzone Outdoor club, where your ticketed seats are located outdoors, however you will also have access to visit the indoor, climate controlled club lounge located just behind Section 450S. The lounge is enclosed by glass windows, so while you will be able to see the field while inside, the views are somewhat limited.
Section 413 is a part of the Outdoor Club seating area at Lambeau field, so your ticketed reserved seat will be outside and exposed to the elements. However, all Outdoor Club ticketholders will also have access to the climate controlled Stadium Club lounge.
Within the lounge you can warm up and enjoy comfortable furniture, private restaurants and upscale restrooms.