Original Dynamo - 300 watts RMS, 10" Driver , Black Enclosure rotates to be forward or downward firing. Original Dynamos had a great power amplifier (similar to the current Dynamo 1000). Retail was $799. A great compact sealed box subwoofer that extends to 27hz in most rooms. 11"h x 11" w x 11" d. 2ea RCA low level inputs L +R and .1 Sub in and also low level RCA outputs to allow for 2nd subwoofer hookup or additional connections. Excellent condition. It was my salesmen sample when I worked for Martin Logan.