well guys, i suppose this is the very tough material named polyolefin used for ESC. as for the standard cheep battery shrinkwrap it's PVC. you just have to know what kind of purpose it is good for. the picture with the battery in this case is a bit misleading i guess.
6 thumbs up!
good value for money. really good for shrinking batteries
4 stars, because it is not really useful for LiPo packs. Same length, as original wrap has weight of 12g vs. 1.5g of original wrap. For other purposes - should be as good as any other heat shrink tube.