The OMNITRONIC CST-6 is a 2-way flush-mount ceiling speaker for indoor 100 V public address systems. It features one 6-inch woofer and one 0.5-inch swivel tweeter, with 20 W RMS rated power, 40 W program power, a 90–20,000 Hz frequency range, 87 dB sensitivity, and 103 dB maximum SPL. The speaker has a plastic housing, white metal grille, 23 cm diameter, 9 cm depth, and weighs 1.60 kg.