Attachment apparatuses

An attachment apparatus comprising a main housing and an attachment arrangement for securing the main housing to a surface-mountable receptacle,

• wherein the main housing is configured to move along a first direction to enter into detachable engagement with the receptacle at a retention position relative to the receptacle, the first direction being an insertion direction defined by a first axis and a first plane;
• wherein the main housing comprises a first portion, a second portion, and a peripheral portion interconnecting the first portion and the second portion which cooperate to define an internal compartment for accommodating items including circuitries, components and/or mechanisms;
• wherein the attachment arrangement comprises a stop mechanism which is operable between an actuated state and a de-actuated state, and a de-actuation mechanism which is operable to de-actuate the stop mechanism;
• wherein the stop mechanism is configured to impede movement of the main housing in a withdrawal direction relative to the second part when in the actuated state, the withdrawal direction being opposite to the insertion direction;
• wherein the stop mechanism is configured to not to impede movement of the main housing in the withdrawal direction when in the de-actuated state, and the stop mechanism is in the de-actuated state when de-actuated;
• and
• wherein the stop mechanism is configured to be de-actuated by application of a de-actuation force through the main housing to operate the de-actuation mechanism, the de-actuation force being in the insertion direction.