Quote Originally Posted by The Vorpal Tribble
Psicrowns are the psionic equivalent of a staff, yup. And it says Manifester Level 11, so these powers can be manifested as an 11th level manifester.
*cough*
(SRD material)

Unlike with other sorts of psionic items, the wearer can use his manifester level when activating the power of a psicrown if itís higher than the manifester level of the psicrown.