The ONLY Pneumatically Balanced Valve Body in a rental/entry level regulator; Single Tube Balanced Valve Body provides improved reliability and performance; Hi-Viz Yellow 36" Hose; Larger diaphragm for optimal response to inhalation; Larger exhaust valve for decreased exhalation resistance; Resilient silicone rubber seat; Precision - ground stainless steel cam and Delrin lever for smooth effortless breathing; High impact housing for rugged applications; Hi-Viz yellow face cover; Simple to maintain