Nylon Spiral Self Tapping Wall Anchor 12mm x 50mm Plastic Drywall Plasterboard Fastener with Conical Drill Tip for Cavity Wall Product Description The 12mm x 50mm Nylon Spiral Self Tapping Wall Anchor is a premium plastic fastening solution engineered for cavity wall / double plasterboard applications. Featuring a sharp conical drill tip and helical spiral body structure, this self-tapping anchor can be screwed directly into the wall surface without pre-drilling a pilot hole.