This speaker enclosure can be connected to any musical instrument amplifier that is capable of driving an 8 ohm load. The internal (passive) crossover of the WorkingMan's 4X10T divides the incoming signal into two frequency bands. The crossover point is 5kHz (frequencies above 5kHz are sent to the tweeter, frequencies below 5kHz are sent to the 10" speakers). The WorkingMan's 4X10T is shipped with a set of four, heavy-duty, removable caster wheels. SWR uses only closed shaft sockets, which prevent air leaks or unwanted noise when the enclosure is in use. Front Slot PortSpring Loaded Rubber Grip HandlesMidnight Blue Carpeting with Stack Lock CornersVibration-Free GrillHigh Quality Metal Input Panel1/4" In/Out Jacks