What is "screwtops"

Usage examples of "screwtops".

Fain would I have someone with opposable thumbs to open screwtops, or what will the use in looting be?

Later, I found some empty pop bottles with screwtops and filled them with the gas, then tied rags around their necks, so that they could be turned into Molotov cocktails in a hurry.

Glass, with tightly fitting plastic screwtops, the three little bottles themselves were worth quite a bit.

Fumbling in the drawer for a bottle opener, he wondered, Will the English ever come into the twentieth century and put screwtops on their beer?