The SA502 amplifier has a 34 dB maximum gain with 2 x 50 watt output. The amp includes three operating modes: stereo, mono or bridged mono as well as three user selectable inputs: balanced stereo (Euroblock), stereo unbalanced mini jack, or high level Euroblock. The SA502 amp has an external 12-32 V trigger, signal detecting auto standby to conserve energy, and dual concentric gain controls for independent channel control. 20 Hz- 20 kHz frequency response. 120 Hz high pass switch. Small size- 1.2" x 3.9" x 4". Rugged aluminum housing. Features: 34 dB maximum gain with 2 x 50 watt output. Three operating modes: stereo, mono or bridged mono Three user selectable inputs: balanced stereo (euroblock), stereo unbalanced mini jack, or high level euroblock. External 12-32 V trigger Signal detecting auto standby to conserve energy Bi-color LED on front panel indicates when unit has power (red) and when signal is sensed (blue). Dual concentric gain controls for independent channel control 20 Hz- 20 kHz frequency response 120 Hz high pass switch (defeatable) Small size- 1.2" x 3.9" x 4" Rugged aluminum housing Optional Accessories: rack mount adapter kit (AC-SA502-RMA)