The decoupling effect of this material is supported by the absorber feet. As with the "Pure" absorbers from bFly, a ring of sorbothane encapsulated between two aluminium discs forms here a damping air chamber. There is also a special gel cushion underneath the feet. An anodised aluminum plate on the top of the bases has an additional absorbing effect and shields against high-frequency radiation. bFly offers even more decoupling with the multi-layer model "Twin", which practically consists of two StoneLine bases on top of each other. The bases are available in the colors volcano black, concrete grey and rose quartz and in the following sizes: 25x35 cm, 44x35 cm, 50x40 cm and 56x46 cm. Prices start at 500 Euro for the single StoneLine and at 800 Euro for the double-layer Twin version.