Basically it is a piece of shop equipment that injects nitrogen into the fuel vapor emission system of a car or truck to test for leaks in the system. At any point during the test a technician will look for signs of leaking nitrogen (smoke) coming from the various pipes and hoses between the fuel tank and the engine compartment if the ECM/PCM has set a diagnostic trouble code for an emissions leak.
Not really sure what it would be worth other than the tanks themselves.
"No good deed goes unpunished!"
'04 Z1000
1987 ZG1000 Concours
1986 Ninja 1000R
'78 KZ1000 Z1R