The OMNITRONIC WPS-4W is a passive, two-way bass-reflex wall speaker for 100 V public address installations. It has a 4-inch woofer, tweeter, 20 W RMS rated power, selectable 2.5 W, 5 W, 10 W, and 20 W power taps, and a frequency range of 90–20,000 Hz. The trapezoidal ABS cabinet includes a white metal grille and pivotable mounting bracket.