The Power Dynamics PDI101 Mono Passive DI Box is a portable one-channel direct injection box for connecting instruments to audio systems. It provides one XLR balanced output, one XLR Combo input and a 6.3 mm jack loop-through output. A 3-way attenuator switch offers 0, -20 or -40 dB settings, while the ground lift switch can help avoid noise from ground loops. The unit has a black metal housing.