Hook: Floor Medium Narrow (Blue Rectangle)The Jukebox: Stellar Hits decoration fits into a narrow blue medium rectangle floor hook.
Hook: Floor Medium (Blue Square)The Jukebox: Stellar Hits decoration fits into a blue medium square floor hook.
How to Get a Jukebox: Stellar Hits Decoration
Cartel Pack Decorations
The Jukebox: Stellar Hits decoration can be dropped from Seneschal's Stronghold Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the Seneschal's Stronghold Pack, include a random selection of items from the Seneschal's Stronghold collection of items. You aren't guaranteed to get a Jukebox: Stellar Hits decoration from a Seneschal's Stronghold Pack, but it is one of the few ways to get a Jukebox: Stellar Hits deco apart from buying it on the GTN from another player.
If you're looking to get a Jukebox: Stellar Hits, 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.