The Isis' reversible Tellurium Copper spikes can be used with (supplied) Precision Coupler bases. The Precision Couplers have a threaded hole on its top face which makes an ideal spike receptacle. Receiving the spike in this way forms an excellent damping termination for the rack, improving sonics over most common spike interfaces. The Coupler bases are excellent floor protectors, and are also fine for use on carpets.