Besides the two following features the Copper Silent 2L is basically identical to the Copper Silent 2 :

Blue Illuminated Fan
The fan and fan case are made of transparent plastic which are illuminated from inside in blue.

3 Selectable Rotation Speeds
In order to reach the exact cooling that your CPU needs, 3 speeds can be selected via a switch. This switch has been attached to a metal bracket and can be installed in any PCI slot. Further an additional control can still be installed. In this case the three fan speed selections mark only the maximum rotation speed.