EVS18SB 18" (457mm) LF Transducer 99 dB Sensitivity, 131 dB Maximum SPL, System Rating: 400W Continuous, (1600W Peak), (28) M10 Threaded Suspension Points. The Electro-Voice EVF-1181S is a high power, front-loaded bass element that can be used in a variety of applications where high quality sound reinforcement is required in a lightweight package. The EVF-1181S utilizes the EVS18SB 18" woofer used FEA optimization for motor, suspension, and electrical design for very low distortion and maximum intelligibility at high SPL levels. The EVF-1181S features make it a professional loudspeaker for any fixed install application. The trapezoidal enclosure is constructed out of weather resistant birch, and coated with EVCoat for maximum protection from the elements. The unique acoustic and rigging design allows for vertical and horizontal clusters to be built using any combination of loudspeakers from the entire EVF and EVH Series, with an assortment of Full-Range, Low Frequency and Subwoofer loudspeakers, it gives you the tools to maximize flexibility of system design, no matter what the application and budget. The innovative input panel provides choice of phoenix style connector (included in all standard models) or the ability to add; a dual NL4 type connector cover plate or gland nut cover plate (for weatherizing applications). An available 70.7/100 Volt transformer kit simply mounts to the input panel for use in distributed systems. All these features give you the flexibility to do a large range of venues with fewer items in inventory and quickly support your customer's requirements.