Great to Take Camping- Save dinner by continuing to grill with a 1lb small cylinder when your 20lb tank runs out. If you just don't want to carry big tank around- With this adapter no more carry of heavy and uncomfortable 20lb propane tank for outdoor cooking.
Great addition for emergency use. Just remember to connect it to the grille first, then the bottle.
My only suggested improvement would be a shutoff valve, but that would drive the price waaaay up.