The FREEFLY WAVE is a small, lightweight and fast high speed camera.
It has a S35 sensor capable of recording up to 1440 fps at 2K during continuous 35 minutes (with a 2TB card) but the fastest would be 9259 fps at 2048×128 px size.
This camera has en E-mount but you can attach an adapter to work with EF, PL, M and Nikon lenses.