This is a water ashtray, at the bottom there are two connections for pipes, one is for the waste water and the other is for the water that rises from the pump, the advantage of using water is that there is no ash smell, to make it work you only need a small pump and plastic/silicone hoses, if you want to add a reserve just use a bottle.

Ps:The small joints are for paper filters and the large ones are for classic 6mm filters