There are three standard thicknesses for each HMI material

45mm (1.75")
This unique double damper material was invented by Halyard and is designed to give the best possible result for the minimum thickness and weight. It is used where big turbo-charged engines are involved, or for vessels where noise is a particular problem – for instance yachts where the engine is boxed into the saloon.

32mm (1.25")
The standard thickness used throughout the industry. Today’s fire zero rated foams have increased the weight and made this material even more effective. 32mm is the choice for any installation where the builder wants an excellent result at a sensible cost. Remember, you can always double layer it in critical areas.

12mm (0.5")
The budget material when thickness or cost are crucial. Although it is only 12mm or half an inch thick, this material is highly effective and will reduce noise by 50% if used properly. You can also double layer it in places.