I know currently there are three available products for this little cameras
3. NB (otherwise also known as Meikon, and their clones like Meike, Paloroid etc etc）
but...have to tell you guys Nauticam has been very aggressive and the housings are under mass production
I am lucky to get one for my friend and to be honest I was shocked by the size and weight of this housing.
The only other housingis the Ikelite for RX100. Ikelite is good except...it is larger and heavier.