The GripIt 20mm Undercutting Tool is designed to create additional space behind plasterboard, allowing the wings of 20mm Brown GripIt cavity wall fixings to open and secure correctly. Ideal for dot and dab walls, insulated plasterboard and double-thickness plasterboard, it removes excess adhesive and insulating material that could obstruct the fixing mechanism. Compatible with standard power drills and adjustable to accommodate different plasterboard thicknesses, this practical installation tool provides a convenient solution for fitting plasterboard anchors where cavity space is restricted. Supplied loose as a single tool.