Unique, comfortable, quiet and safe. Rated #1 in scavenging efficiency in independent clinical trials – the Porter scavenging system is the only double mask (mask –within-a-mask) system. The Porter double mask scavenger breathing circuit features an outer hood and the option for either a flexible autoclavable or single-use-disposable inner liner. The inner liner creates a complete, yet comfortable seal around the patient’s nose – thus assuring the Porter mask’s superior scavenging efficiency. Porter breathing circuit packages include: 3 or 2 liter bag, fresh gas tubing, scavenger breathing coaxial tubing, adult or pedo autoclavable hood (with 3 inner liners) vacuum line hose and options to include the Porter Automatic Vacuum Switch or In-Line Vacuum Control. The Porter scavenging system compatible with Porter and Matrx flowmeters – and easy to retro fit to most other modern flowmeters. It is recommended to replace breathing circuits every two years.