Folks here in the US call them "beer coozies" (why I have no idea). I second the nomination for wraps - I have one for every large format lens, even if it has both front and rear caps. I label each wrap with the lens that goes in it so I don't have to worry about confusing them, and it helps to keep the lens caps organized - open the wrap just enough to remove the lens, drop the caps in, close the velcro on it again, and voila!