Probably the entry-level planar headphone these days, but arguably only worth it if you're not willing to reach for the HD6XX. This is neutral/flat, with a small dip around 2kHz, and some heat in the upper treble via the Stealth Magnets. Described by some as a mini-Sundara (presumably the original release), it has a great level of detail and resolution for the price, but imaging is a little fuzzier than some key competitors (eg. K612, DT990, DT880).
Back at its lower price point, you will need an amp to supply this enough current to make it shine, with its sensitivity being 91 dB. Great review with FR measurements here.
Enjoy!
Upvote for the detail, very tempting…