This is Shen's upgraded hybrid bass with a carved spruce top and laminated back and sides.  It differs from a 150 in that it has a figured maple veneer on the back and sides as opposed to a plain hardwood veneer. In addition, it has upgraded tuners and tailpiece.  I am selling this one for the same price as the 150 (a $400 discount over usual price of 180) as it has a cosmetic piece of maple sliced into the neck, next to the fingerboard, which I assume is to repair a flaw in the maple.