This is a 900mhz VTech #9111 phone with the molded into the plastic power supply specs as a "classII 9VDC 300ma UL 8L55 power supply Only".
The power supply says class II (with 2-prongs),117VAC 60HZ 6.5W input, 9VDC 300ma output, LEI-4, UL 12J2 US listed E82456 US model #280903003C0.
It is not very heavy, but seems like it is much heavier switcher.
The open output today is 17.55VDC taken with a true RMS Sperry model 350A meter.
Interestingly enough, the non-molded numbers (the branded in with stamps numbers) on the prong side say "0018", which is only 0.45 from to 18.
I had several of this model phone and don't know what the other wall-warts said, and they may have became intermingled, but "the same" models were run from MSW to many other DC voltages, with no catastrophic failures.
This one is Puke Purple, the other one was Gag Green.
There were 2 Gag Green ones, and at least another nasty color too.
The phones are nice, but it would not bother me if one blew up!
G-