A clip for securing a sleeve to the body of a piezoelectric actuator in an actuator assembly, the clip taking the form of a band comprising first and second axially spaced ring-like members joined by a plurality of inwardly facing substantially arch shaped sections, the arch shaped sections defining the minimum inner diameter of the band, whereby axial displacement of the ring-like members way from one another causes flexing of the arch shaped sections to increase the minimum inner diameter of the band while axial displacement of the ring-like members towards one another causes flexing of the arch shaped sections to reduce the minimum inner diameter of the band thereby, when in use, to increase a clamping force applied to the sleeve.