What the part is
The ABB ACS800-U1-0006-5+B901 is a wall-mount industrial drive in the ACS800-U1 family, sized to the 5HP class on this catalogue line, and carries the +B901 option code that distinguishes it from the base ACS800-U1-0006-5 configuration.
Panel-side notes the spec needs to drive
The drive weighs 7.71 kgs, so a single installer can lift it into a wall-mount cabinet cut-out, but the cabinet still needs the U1 frame footprint and the dedicated clearance ABB requires around the heat-sink fins for forced-air cooling. The ACS800-U1-0006-5+B901 is the 5HP catalog line from ABB, listed as a Motor Drive under the Drives branch.
Sourcing posture
Where a buyer is migrating a panel to the current ACS880-01 generation, the same-function class on record is the ACS880-01 series; one sibling in that set, the ACS880-01-021A-5, lands at 7.71 kgs, which matches the ACS800-U1-0006-5+B901 cabinet mass and is the natural cross-shop candidate when the BOM is being re-engineered around the newer platform.