Soundstream SM4.1000D micro amp. Waterproof so it can be used in marine applications also. Rated at 90wrms x 4 @ 4ohms, 125wrms x 4 @ 2ohms, or 250wrms x 2 @ 4ohms bridged. This amp is tiny - approx. 3" x 7.5", so it will fit almost anywhere. New. $80 shipped.