We released the CA2 series in 2002 and discontinued the CA1 series in 2005. The mounting dimension of the CA2 cylinder is compatible with the CA1 series.
The major difference between these series are as follows:
(1) Lubrication type was consolidated to the non-lubrication type.
(2) Shape of the cushion valve
(3) External color of the covers
For the CA1 series, we had to add "N" to the part number to specify the lubrication type. However, such identification is not required anymore for the CA2 series. Also, in August 2012, we released the CA2-Z series, the renewed CA2 cylinder.