The NEOPERL PCA Perlator 1.8 GPM regular female vandal proof 55/64-27 is pressure compensating. The pressure compensating design helps to maintain a constant and comfortable water flow regardless of pressure fluctuations. This aerator also features an anti-clogging light blue dome screen that filters sediment. The Patented single piece construction is virtually unbreakable and lime resistant. The laminar feature provides a constant crystal-clear stream non-aerated, which prevents airborne bacteria from entering the water through air contamination. The exterior rotating sleeve of the aerator can only be installed and removed with a key so it prevents tampering. This makes the aerator ideal for use in bathrooms in commercial and multi-family buildings. Solid brass housing with a chrome finish.Pressure compensatingLaminar streamSolid brass with chrome finishLead freeHelps to reduce bacterial contamination into the waterANSI/NSF 61, ASME A112.18.1M, CSA B125, AB1953, S-152