Most commonly you'll find semi-weighted MIDI controllers in 49‑key and 61‑key configurations.
Common options shown are waterfall-style semi-weighted keys and hybrid synth-feel semi-weighted keybeds.
Many models include multiple knobs/encoders and long-throw faders. Typical configurations shown are eight encoders with nine long-throw faders, or nine faders paired with accompanying knobs/encoders.
Pad counts typically range from eight to sixteen. Common features include velocity sensitivity, RGB/backlighting, assignable mapping, and—on some models—polyphonic aftertouch.
Common connectivity includes USB (bus-powered or class-compliant USB‑C) and, on some models, a standard 5‑pin MIDI output for controlling external hardware.
In the listings reviewed, 49‑key models weigh roughly 8.85–12.25 pounds, while 61‑key models range about 9.65–15.05 pounds—so portability varies by model from lightweight to moderately heavy.