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