CHRISTINA G This doesn't have a zipper at all. It's a simple thin (blouce fabric) sack made of silk fabric.

ALLAN G The Grand Trunk silk sleeping sack does not have zippers. Both sides are sewn together up to about 3/5's the way up. From there it is open. There are 2 sets of strings on either side which you tie to close.

DESIREE S Sleep sack does not have a zipper.

SCOTT L No zipper.

JEAN S Douglas - The product does not have a zipper and it does not open all the way into a rectangular blanket. It open half way on both sides and has little ends that can tie together on the top of the open sections.

CHRISTIAN S I don't know which silk it is, but I thought it was a bit course for as it goes. Most likely to help it breath. Considering that, thread count might be a factor for you. However, I used it as a bag liner and it was truly horrible for that task. It quickly twisted up and bound me so tightly that several of the button loops tore off within the first few minutes of use as I tried to free myself. By itself, maby - as a liner - I think you would be better off stitching up an old cotton sheet.

MICHAEL B I do not know what type of silk it is but this sleeping sack is thin and light. I would say it is good for summer by itself in temps above 65? and for a little extra warmth in the shoulder seasons. It also serves to keep your sleeping bag clean and free of body oils.

Judith M Sorry, I gave it as a gift. Don't know.