Many systems support duets via two mic inputs and provide mic controls such as independent mic volume, adjustable mic sensitivity, balance, echo (analog or digital), and—on some units—digital key/pitch control.
Common connections include Bluetooth streaming, 3.5mm aux/line‑in, RCA A/V outputs for TV connections, and support for USB flash drives or SD cards on some units.
Some models include built‑in color TFT screens (common sizes shown include 7" and 4.3"). Other compact units omit a screen but provide RCA A/V output so CD+G lyrics can be displayed on a TV.
Listed output specs vary widely across models: examples include a 35 W peak (25 W RMS) amplifier, a 40 W peak (10 W RMS) spec, and some systems that list up to 60 W RMS total output. Verify whether a listing shows peak or RMS power when comparing units.