BEHRINGER ULTRA-DI PRO DI4000 Professional and multi-purpose 4-channel direct injection box for stage and studio applications Provides impedance and signal matching for the direct connection of instruments to mixers and amplifiers Ultra-flat frequency response due to renowned BEHRINGER OT-1 transformers Allows direct connection to speaker outputs with up to 3,000 Watts +20 dB gain switch for preamplification of low-level signals