Pneumatically balanced – -Chrome Plated Brass Valve results in smooth, easy breathing; Reversible on-demand valve, can be converted from right – handed hose configuration to left handed hose configuration; – -Adjustable Dive/Pre Dive switch: Large venturi lever has a soft rubber grip, which makes it easy to locate and use; effort; Improved ergonomic exhaust B-channels bubbles away from the field of view and reduces exhaust Orthodontic Mouthpiece with dual color tabs