Hook: Floor Medium Narrow (Blue Rectangle)The Large Field Generator decoration fits into a narrow blue medium rectangle floor hook.
Hook: Floor Medium (Blue Square)The Large Field Generator decoration fits into a blue medium square floor hook.
How to Get a Large Field Generator Decoration
Flashpoint decorations have a chance from dropping from a certain flashpoint. They are not a guaranteed drop, but have good chances of being looted from the final boss and a high chance from the bonus boss. Hardmode flashpoints have a higher chance of dropping a decoration than storymode flashpoints.
Approximately one decoration is dropped per hardmode flashpoint, and each flashpoint drops a different type of decoration. The Large Field Generator decoration is dropped from the Kaon Under Siege Flashpoint.