The flushless urinal comes in two varieties; a cartridge insert or built into the fixtures trap. Both work on the same principal though. A liquid sealant that is lighter than water , allowing waste to pass through it and into drain lines, is inside the trap or cartridge. The sealant remains on top of any liquid in the trap, forming a seal in the pipe. This blocks any odor or sewer gas from escaping into the room.
Since there are no flushing mechanisms, the urinal units actually cost less than a standard flush urinal. The money-saving does not end there though. Since no water is used, it cuts down on the cost of operating the unit. It also negates most future maintenance work since there are no moving parts in the unit.