Neoperl has improved on a common issue. Lime build up. The Pressure compensating cascade SLC is the ultimate defense against lime. The cascade construction already prevents lime build up, but add the soft silicone tip and removing lime is as easy as rubbing a finger across the tip of the aerator. This 1.5 GPM is dual threaded, with a solid brass housing in chrome. WaterSense certified and Lead free.Pressure compensatingSimply rubbing the flexible silicone tip eliminates lime build-upAerated streamSolid brass with chrome finishLead freeANSI/NSF 61, ASME A112.18.1M, CSA B125, AB1953, S-152, WaterSense