400RB-IV Series Specifications: Output Power: 400RB-IV: 180W @ 8 ohms 280W @ 4 ohms Input Section: Maximum Input Level With -10dB pad Input Impedance Send output impedance Return input impedance Tuner Output Impedance Direct Output Impedance Equalizer: Bass Lo-Mid Hi-Mid Treble Voicing Filters: String Bass Button Contour 0.6V Rms 16V Rms 1M Ohm 220 Ohm 50k Ohm 10k Ohm 500 Ohms =10db @ 60Hz +6b/-10db @ 250Hz +6b/-10db @ 1kHz @ 7kHz Presence Noise Cooling: +11db@20Hz +2db@50Hz / -10db@500Hz / +9db@10kHz 90db referenced to 700W/480W, "A" weighted Continuously Variable-Speed Fan Amplifier Protection: Full short circuit, thermal, & RF protection. Stable into reactive and mismatched loads. Five-second muted warm-up. Dimensions (HxWxD): 3 1/2" × 17" x 8% (2 Rack Spaces) Weight: 15lbs https://static1.squarespace.com/static/52d881e0e4b093afad1a2ae2/t/54a3103be4b0d6033e37f765/1419972667560/400RB-IV.pdf Included accessories are only the original power cord. (00841.)