Cheap, but not very reliable
I have two, one of which leaks at the plastic patch that holds the inlet. A tiny leak, but a leak nonetheless. One drawback is that it's impossible to orient the water inlet. You have to tighten it all the way because there's a rubber gasket. There's no choice of orientation for the filling hose. Also, the outlet is very small, 12 mm in diameter, tapering to 10 mm to fit a 10 mm hose. If you use a 12 mm hose, it's best to cut off the tapered part. Also, the part is made of very soft plastic and crushes when tightening the clamp. It's best to replace the part with a better quality one.
Another drawback is that the outlet is vertical. So, there's no choice of orientation, but if it's under a floor, space will be needed, as the full tank is quite high, which is an advantage for capacity (120 liters for a size identical to a 100-liter Vetus tank), but you need at least 55 to 60 cm of available height.
I replaced the inlet elbow with a TrueDesign, mounted with Loctite 55. This way, the hose can be oriented in any direction.
I tested at a pressure of 1.2 bar, which is necessary to ensure a seal when the filler pipe is full to deck level. One of the tanks is OK, the other has a very small leak.
It should also be noted that the water outlet is located in the middle of the tank and extends about one cm inside. On a horizontal surface, the tank empties almost completely. However, when placed in a trunk with a sloping bottom, the usable capacity decreases. In my case, the bottom is 30 degrees, and I'm losing 10 liters per tank.
I tried a Plastimo to replace the leaking one. The hose connection system is different, allowing for reorientation, but I was unable to achieve watertight connections. So I ordered a new CANsb.