The HM is suitable for attaching items to board materials such as plasterboard with a thickness between 5mm and 18mm. The metric internal thread of the HM allows you to remove and refit the item several times. The claws around the neck of the fixing penetrate the board and prevent it from rotating while being installed. HM is suitable for pre-positioned installation. During installation, the arms expand open and press onto the reverse side of the board. To achieve this you can either use a dedicated installation tool, a battery operated screwdriver or screwdriver for installation. If using the latter method remove the pre-assembled screws first. Place the item for attachment over the pre-installed shell of the fixing, install the screws and expand the fixing.