In many engineering applications there is need to reduce the level of vibrations that are transmitted from a source to a receiver. Amongst several different techniques, the most commonly adopted solution is to interpose an isolation mount between the source and the receiver. Ideally, a vibration isolation mount would have a high static stiffness to prevent too large a static displacement to occur, but a low dynamic stiffness which reduces the natural frequency and extends the frequency range of isolation. For linear mounts these two features are mutually exclusive. However, an improved compromise can be reached by employing nonlinear mounts. In this book the advantages and the limitations of nonlinear isolation mechanisms with a High-Static- Low-Dynamic-Stiffness(HSLDS) characteristic are investigated. The aim is to provide the fundamental principle behind HSLDS vibration isolators. Both static and dynamic analysis are presented. In particular, nonlinear dynamics aspects are also discussed as the system can be approximated to a Duffing oscillator. Finally, experimental results are used to show the potential of the HSLDS vibration isolator.