The Stand has no appearance (although the picture suggests the area around the individual it targets has a gas-like substance surrounding it).
Memory of Jet's ability is to target a particular location or individual, then isolate the target from the cognition of all other people, to stop anyone from getting access to it. Under the effect of this Stand, all people cannot enter the targeted location out of their own will because the location itself and the ways toward it are excluded from their minds, except Teruhiko himself. When Teruhiko activates this ability to confine Akari Hirai, though he is unaware of his Stand ability, the roof and building gap where Akari is trapped into seem to completely disappear from other people's sights, hence no one ever comes to the roof and looks down to the gap. The effect of the Stand is maintained on an annual basis, as long as Teruhiko still has the will to use this ability.
It is suggested that only the person who is guided by Teruhiko can get access to the targeted location. With the leading of Teruhiko, Hanae Orikasa is the only one getting to know Akari being trapped into the building gap.
Teruhiko names this Stand after the black amber necklace he gave Akari long ago.
While the ability can last as long as desired, it is unknown how long the Stand power lasts on its own, and whether or not Teruhiko needs to continue to visit the target to recharge it.