Hook: Floor Small (Green Square)The Gemini 16 decoration fits into a small green square floor hook.
Hook: Floor Medium Narrow (Blue Rectangle)The Gemini 16 decoration fits into a narrow blue medium rectangle floor hook.
Hook: Floor Medium (Blue Square)The Gemini 16 decoration fits into a blue medium square floor hook.
How to Get a Gemini 16 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 Gemini 16 decoration is dropped from the Flashpoint.