The QB4-1100 is a power tetrode for use in AM and FM transmitters from top HF to low VHF and will cover the Band II broadcast band. Output power depends on the modulation used, ie duty cycle, and anode voltage. as an example at 110 MHZ an SSB transmitter with 4,000 Volts on the anode can generate 650 Watts.

More information on tetrodes is available here: http://www.r-type.org/static/grid02.htm

The specification of the QB4-1100 is here: http://www.r-type.org/pdfs/qb4-1100.pdf

It is used and the glass is intact. There is no visible damage.
I have no tube tester but used a multimeter to test for continuity. There is continuity between two pins.

It is a beautiful piece of industrial art and is sold as such. There is no guarantee that it works!