The Mungo MU - Multi Universal Nylon Plug is a universal heavy duty Nylon Plug. Used for many types of building materials with indoor and outdoor applications. The MU Multi Universal Nylon Plug has multi-functional applications and excels in hollow walls with its unique knot form. Its flexibility arises in its automatic collar detachment system which allows for pre-installation and through fixing. It is also designed to prevent premature expansion during installation.