ICFS Anchor Fasteners Nylon Hammer Plug NHF provides a professional and secure method for fixing doors and window frames. It has an elongated nylon plug body incorporating a countersunk collar and is supplied complete with a heavy-gauge screw in either countersunk or hexagonal head. Advantages: Special anti-expansion design lets the user drive both plug and screw into the hole together without the plug expanding before it is fully inserted. Side-links stop the plug from breaking open during insertion, ensuring positive action when the screw is driven in. Screw guide stops the screw from penetrating the sides, by ensuring positive tracking down the entire length. M-teeth combined with side-links and screw-guide, ensure the entire plug face is forced against the walls of the hole, for enhanced grip in soft materials. Offset block profile allows the plug to hold firmly against the sides of the hole when expansion begins. Countersunk collar reduces the risk of bi-metallic corrosion when fastening non-ferrous fixtures. Nylon material absorbs vibration and noise. Extended expansion length guarantees maximum load-bearing capacity. Advice: For installations in perforated and hollow bricks, drill with a rotary action only (hammer switched off). A Short expansion plug is recommended for use in concrete, natural stone, and brick. Extended expansion plug is recommended for use in hollow brick, gypsum aerated concrete, and sandstone.