It means One (1) Twenty foot, full container load for a minimum order. What is 1x20? -- One twenty foot container FCL -- Full Container Load
How big are the barrels? You are missing the third part of the equation.
a flask
20
1x20 2x10 5x4
1x20 2x10 4x5
250 barrels
453,942 barrels.
There are several different types of barrels. Among the most common uses of "barrel" are the uses involving guns (where the bullet is fired from) and a carrying container or casket such as a beer barrel.
The Ordered Pairs are 1x20, 2x10, and 5x4.
That depends what the barrels are of and how much the individual barrels weigh.
only if it is illegal to take from the container (red icon), those arent your containers so items disappear