As you can see, there are three versions of this one.  serial 1.0 is for Leverage versions before 1.5 (builds prior to 1.0.5q, of which the most common is 1.0.4).  serial 1.5 is for Leverage 1.5 on 1.x Newtons such as the MessagePad 100 and the MessagePad 110.  serial 2.0 is for Leverage 2.0 on 2.0 Newtons such as the MessagePad 130 and MessagePad 120s with the Newton 2.0 operating system.