Hook: Floor Medium (Blue Square)The Medical Tower decoration fits into a blue medium square floor hook.
Hook: Floor Large (Purple Square)The Medical Tower decoration fits into a large purple square floor hook.
How to Get a Medical Tower Decoration
Cartel Pack Decorations
The Medical Tower decoration can be dropped from GEMINI Alliance Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the GEMINI Alliance Pack, include a random selection of items from the GEMINI Alliance collection of items. You aren't guaranteed to get a Medical Tower decoration from a GEMINI Alliance Pack, but it is one of the few ways to get a Medical Tower deco apart from buying it on the GTN from another player.
If you're looking to get a Medical Tower, the easiest way to get it is to head to the Galactic Trade Network (GTN) in SWTOR and buy it with credits from another player. If it's very rare and not available on the Cartel Market, you could try buying from the GTN and hope you get it.