Approximate size of the 1 liter oak barrel is about 5 1/2″ from head to head and about 5″ in diameter.? 1 liter is about 1/4 gallon size. The 1 liter oak barrel will age the fastest of all the oak barrels we offer.? You can get about 2 years of flavor influence on? your drink in about 4-6 weeks.? What we love about the 1 liter charred oak barrel is that you can get a quick flavor response on a small batch to see if you like the recipe and flavor.? If you like it then you can recreate it in the 2 liter oak barrel.? You will love the flavor of our barrels.