A tough fibreglass cloth, with a sealed metallised skin, so it cannot absorb oil.

 

Heavy duty in appearance and fire zero rated, the insulation will not tear or fray.

 

32mm materials: Offers a 15dB reduction at 1000Hz. Noise doubles every three decibels, so this is nearly three times as good as the 12mm. It also holds a good performance at lower frequencies, making it excellent with larger engines. Good choice for mid-price range.