Composition

Iso-Bearings are composed of two parts, the globe and the cup. The Globe is a unique elastomer with an extraordinarily high damping factor, dissipating nearly 100% of the energy that enters the globe. The Cup is machined from a single piece of Delrin, a plastic-like material with excellent damping characteristics. The Delrin cup is then bonded to a brass baseplate, and a thin layer of elastomer is applied to the bottom for additional isolation. Iso-Bearings are so effective that Audio Prism used to do a demo at shows where they would smash the head of a hammer into the globe of an IsoBearing 3.3 and it wouldn't bounce!

IsoBearing 2.5 vs 3.3 
IsoBearings are designed to accommodate any type of component. The 2.5 is designed for smaller or lighter components where a high-level of vibration control is essential. The 3.3 is designed for heavier components which require a greater level of vibration control, especially at lower frequencies.

Specifications

IsoBearing 2.5
Capacity: 4.4 Lbs per globe (~13Lbs per set)
Globe Diameter: 1"
Base Width: 1.5"
Total Height: 1.2"

IsoBearing 3.3 
Capacity: 15 Lbs per globe (45Lbs per set)
Globe Diameter: 1.3"
Base Width: 2"
Total Height: 1.6"