Long lasting toilet deodorising blocks for use in channel and single urinals. Freshens the urinal bowl. Water soluble and do not evaporate. Do not contain harmful PDCBs, making them safer to use, even where children may be present. The blocks are stable until water is flushed over them when they become activated and reduce any fats, organic matter and wastes present. Each time the system is used, a cleaning solution is flushed into the pipes to keep them clean and clear.