2 Items Following Same Serial Number Name Series?

Is it possible to have 2 items follow the same serial number naming series? I have 2 items, one for 115V and another for 230V versions of the product. Is there any way to have the automatic serial numbers assigned sequentially for both items?


120V - SN # ECH001
120V - SN # ECH002
230V - SN # ECH003
120V - SN # ECH004