Hook: Floor Large (Purple Square)The Selkath Kolto Tank decoration fits into a large purple square floor hook.
How to Get a Selkath Kolto Tank Decoration
Cartel Pack Decorations
The Selkath Kolto Tank decoration can be dropped from Gatekeeper’s Stronghold Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the Gatekeeper’s Stronghold Pack, include a random selection of items from the Gatekeeper’s Stronghold collection of items. You aren't guaranteed to get a Selkath Kolto Tank decoration from a Gatekeeper’s Stronghold Pack, but it is one of the few ways to get a Selkath Kolto Tank deco apart from buying it on the GTN from another player.
If you're looking to get a Selkath Kolto Tank, 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.