This unit has the same outputs as the LB2633-001 but,  in addition,  it provides a regulated DC output up to 16V.DC. and up to 3 amp max.   This regulated output is SMOOTH DC and is monitored by a red LED digital display.  Electronic experiments almost always require a smooth DC supply (like a battery).
The term "regulation" means that the voltage setting does not vary whether no load or full load ... the set voltage remains constant.   The outputs of unregulated power sources fall as the load current increases and also with changes in mains voltages.    A "Regulated" output should not vary for any of these reasons.

This low cost  instrument is not precision regulated,  but the regulation is to a useful degree.  

Replaced by LB2628-002.