Hollow Metal door clips can be used in hollow metal doors, and replace the need for reinforcing channel in all Anemostat vision frames and louvres when fitted to 44mm thick doors. They are manufactured from 20GA cold rolled steel. The clip is inserted between the door skins with the barbed sides outside the door skin, and then snapped into place, fitting flush with the door cut-out. The number of clips required will depend on the size of the aperture. Please note that when using HM-Clips with LoPro vision frames extra caution should be taken to ensure door cut-out is exact. Do not oversize the cut-out.