I know NOTHING about this. I got AA batteries to stick in the battery compartment and it turned on and says "missing sync", I'm assuming because there's no input? No idea how to test it use, so selling as is for parts, definitely not dead but can't verify complete operation.

The Tektronix WFM90D Portable Handheld Vectorscope Waveform Monitor is a digital oscilloscope specifically designed for on-the-go use. Its compact and handheld design makes it convenient for professionals in the field to perform accurate measurements and inspections. Manufactured by the reputable brand Tektronix in the United States, this model offers reliable performance and advanced features for analyzing and acquiring data in various industrial applications.