These apparently are the smallest MIDI controllers you can buy.
The NMSVE (Noise Machine Straight Vibin' Edition) are Bluetooth MIDI controllers with 12 buttons, expression knob, and aa slider. Launched on Kickstarter in 2020 and it went well so they are now available via the
https://thisisnoiseinc.com/ website priced at $79.99 or available in a build kit version $59.99
New Stereo features and FX algos
From recent Brighton gig
Built on Takt and Tone tech its beats and synth
With Delta CEP A and friends