The Hollis 500SE + DC7 DIN is a regulator pairing a proven first stage with a servo-controlled second stage for scuba diving gear. The 500SE second stage uses a servo-controlled valve to provide airflow control suitable for air and trimix dives in a side-exhaust configuration. Built for backmount and sidemount setups, this regulator pair emphasizes reliable performance across demanding diving conditions.

The DC7 DIN first stage delivers high performance with an over-balanced design that maintains stable intermediate pressure as depth and gas density increase. Fixed hose routing supports both backmount and sidemount configurations. Environmental sealing helps prevent internal corrosion, contaminants, and icing. It is designed for coldwater performance under CE standards, Nitrox compatibility to 40%, and offers 2 High Pressure ports and 4 Low Pressure ports with DIN/300 bar compatibility.

The 500SE second stage features a pneumatically balanced servo valve system for consistent airflow. It includes a patented orthodontic mouthpiece for comfort and reduced jaw fatigue, and comes with a 30 in. maxflex hose. The unit is easily disassembled without tools, and can be serviced underwater if necessary. It supports left or right positioning with a boltsnap tie point and a side-exhaust design for practical use in diverse diving configurations.