Loudspeakers based on 15 inches speakers. 2.5-way, coaxial design. Bent plywood case. Pure copper speaker terminals. Internal copper-silver cabling. Loudspeaker baskets are grounded and connected to the external socket, which should be connected to the 230 V grounding pin or to the amplifier housing. Triple-step tone control. Adapted to work with tube amplifiers with 4 ohms output.