WHAT DOES IT FIT?
Small to Medium DSLR (e.g. Canon 5D or Nikon D750 without battery grip) with one small-to-medium lens attached. If a very small lens is attached then a another spare lens might be possible too.
Almost any mirrorless camera (Sony A7IV, Fujifilm X-T4, Nikon Z6, Canon EOS R, Olympus OM-D E-M1 etc) with small to medium lens attached. Plus maybe a spare lens too.
Leica M10 with 1 lens attached and another to the side.
Compact medium format cameras with a small-to-medium lens attached (e.g. Fujifilm GFX 50S with 63mm lens or Hasselblad X1D II with 80mm lens attached).
Small foldable drones such as Mavic Air 2 or Mavic Mini 2.