The Paso TR400-SX + UT60 horn speaker unit consists of reinforced fibreglass. It is waterproof and weatherproof. It can mount four 60 W/16 ohm UT60 units (for a total output power of 240 W) or four 150 W/16 ohm UT150 units (for a total output power of 600 W). The horn is built so as to synchronise the sound waves generated by the single units. In order to ensure high efficiency and excellent intelligibility of speech, each unit uses its own separate curved horn path to scatter the sound energy produced, thus avoiding interference effects.