Package include: 50 PCS Double-Headed Zinc Plated Finish Screw，screws are 1-3/16" long. Distance between two heads is 5.5mm (0.22inch), fit for most keyhole hangers for hanging frames. 4-in-1 Double headed screws : Works with picture wire, and frame back hardware, D-Rings, wire and key holes, sawtooths & keyholes, picture hangers and art galleries Double-headed anchorless screws support 30 pounds when installed in drywall (no anchor) and up to 100 pounds in wood studs. No pilot hole required - sharp self-drilling tip easily installs with a phillips screwdriver. Quality material - durable and not easy to rust, lightweight and convenient to store, you can use them multiple times and will not break easily. Notice: the double-headed screw hangers are suitable for drywall or plasterboard wall, but not for concrete or ceramic walls. Widely used for at office, art galleries or home easily hanging kinds of frames, artworks, exhibition painting, shelving, mirrors, shelf straps, decoration fixing, calligraphy, gallery pictures, clock, posters, curtain rods and other small items. 4-in-1 Double headed screws : Works with picture wire, and frame back hardware, D-Rings, wire and key holes, sawtooths & keyholes, picture hangers and art galleries