To add on to Wulf202. It was derived from the child's favorite blanket and like children do, you bring it everywhere...I mean everywhere. Always in your carry on luggage, on the bus, in your back, and so on.

7 Years in the Army from active duty to reserves and never once tied this into a poncho.

I also have several. One in every vehicle. One in every pack. $40 is a bit expensive. Go the surplus store. Sometimes their used stuff is in great condition. Or check out a reputable online store that sells used stuff too and will tell you what condition the liners are in.