Reading the code
The ABB ACS550-U1-03A3-4+L502 is an ACS550-series low-voltage AC drive, with the U1 designation pointing at the wall-mount frame and the +L502 suffix selecting a documented factory option on top of the base 03A3-4 rating. Catalog placement is Motors & Motor Controls › Drives › Motor Drives, which is the file path a buyer checking the ABB drive family would expect to find a general-purpose VFD under.
Frame and handling
Mass is 4.54 kg on this U1 wall-mount build, light enough for one technician to handle and seat against a standard sub-panel without a separate support bracket.