US federal barrels
A Federal US Barrel is 31 gallons which is about 117.35 liters. This unit is normally used for apples, potatoes and other agricultural products.
UK fluid ounces
A UK fluid ounce is about 28.41 milliliters, a little smaller than the US fluid ounce of about 29.57 milliliters. So 1 US fluid ounce is about 1.04 UK fluid ounces.