Sleeping Bag Liner and Camping Sheet – Silk Like Material for Travel - Has Full Length Zipper

Liner without sleeping bag question. for use at sea base in florida is this all that is needed? read review about this. liner alone warm enough?

Does the zipper only open one way, or can you unzip just the bottom?

What is the size of the pouch?

How much does the liner weigh? Looking for something to take on a backpacking trip.