They typically look like a clarinet and are fingered like a saxophone or flute (some also support trumpet fingering).
They (usually) have the limitation of playing only one note at a time but, in exchange, they provide for very expressive playing by responding to breath pressure and bite (the latter using a reed-like arrangement)
Current models are available from Yamaha, AKAI, and Synthophone
Here are my three wind controllers. From top to bottom they are:
- Yamaha WX7
- Yamaha WX5
- AKAI EWI USB
It took a while, but this link helped me repair it to the point that it could be used.
Wanting something more current and stable, I bought the EWI USB and then, finally, the WX5