Run away, far away from the shelter-half. We had a thread about shelter-halves a few weeks ago in W&SS. The overwhelming consensus from those of us who've had the absolute displeasure of being issued the shelter-half and tent poles and have had to use them is that the ensemble is heavy, un-weather resistant, and not worth $20. One guy said he was able to stay warm enough to survive in dry snow; and I used to use mine as a floor next to a cot.
Now, if you could get like 6 of them for $20, that might be a deal in rustic fabric that you could sew into a cool knapsack, haversack, or messenger bag. Other than that, I wouldn't touch a shelter-half ever again.