I found at the local 99 cent Store (the big chain with many stores in large city), an insect viewer. It is a snapped together green on green lastic container. It is a lot like 5-1/2" long plumbing tee used in drainage plumbing, in that the ends are removable and the top (Tee) is also movable for better viewing and access. The ends are dark green and are vented with the same hole size as many screens. The smallest fruit flies can get through, but with the placement of a piece of apple or other fruit, they seems to only get out by accident not by intention. I notice when the flies do get out, they hang around and want to get back in. The other dimension that I need to state is the diameter. i.e., 4" and the upper lid being about 3-1/2" in diameter. For 99.99 cents, one cannot go wrong when one is a nubie as I am and not having enough nymphs yet, and in my case no adults to warrant much more than this to start with. I thought that I would pass on my finding for those who are making habitats for new nymphs or a solitary adult.
Now I have been using this insect habitat for over a week now and I can see that it has real merit. The first of a few L2 Ghost nymphs is entering into the first signs of his next molt and I can see that there is plenty of room for it to manipulate and do its thing to extracate himself from his exoskeleton. What a trick! The others are not yet there, and they are in no way lacking room. Of course the useful volumn of such a space is increased with the amount of hanging areas one provides. In my case I have some strips of coco mat that I bought yesterday for a substrate for my newly arrived oothecae. Anyway I thought that I would give you all an update from one who is actually using this $1 find.