It's a round tube:2 circles on outside, round all around
I clyinder is like a can. An object with two circular bases and round sides.
Front to Rear. Looking at the Engine. Left Side 1-2-3 Right Side 4-5-6 Hope This Helps.
Usually if it is trans-mounted the one closest to the passenger side If it is conventional the one closest to the front of vehicle
Be it is marked of with marks that a graduated so to provide accurate measurements. One source states that the word graduated became a popular name due to the method of making the Cylinder....