A tamper-evident cover 256 for a component, the component comprising: first and second portions; and an actuator mechanism for moving the first and second portions or allowing the first and second portions to move relative to one another; wherein the cover comprises: a cover portion 262 defining a cavity configured to receive the actuator mechanism of the component so as to prevent access to the actuator mechanism from the exterior of the cover portion; and a retention barb 260 connected to the cover portion and housed within the cavity formed by the cover portion such that it is inaccessible from the exterior of the cover portion, the retention barb being configured to engage with the component so as to retain the cover portion over the actuator mechanism.