If you only have one Rabbit the standard water bottle works just fine.
For more Rabbits it’s a lot easier two put in an automatic watering system
This type of system is not two hard to install a valve for rabbit’s hooks to the cage
then to a plastic line the line gets connected to the water supply
We took a five-gallon bucket installed a toilet fill valve then a connection to the valves
This supplies water to our nine cages and only requires us to clean the valves weekly.