Review: The Hollis DC7/ 500SE combo will definitely make you stand out from the crowd! The second stage is a side exhaust regulator, which have seen a revival of popularity in recent years. The main advantage of side exhaust regulators is that exhaled gas bubbles are sent toward the rear and away from your face, to prevent your vision being obscured.
Also, from a travel perspective, the shape of this second stag side exhaust regulator is longer and thinner than that of a normal regulator; which for some people will make it easier to pack; depending on their packing style and baggage. This ergonomic design is either going to really appeal or strongly put off some people. It all comes down to personal preference!
With a weight of 1.1kg (2.4lbs), the Hollis 500sE / DC7 is lightweight but still about 0.2 – 0.3kg heavier than most other travel regulators. Honestly, you probably won’t notice this weight difference much, but you will notice it’s overall shape of the second stage making it easier (or more challenging) to pack.
The first stage features an over balanced diaphragm, which provides progressively greater air delivery pressure at depth and gas density increases, making it great for deep dives or tech diving. It is environmentally sealed to prevent internal corrosion, containments and icing of the first stage.
Furthermore this regulator is designed to pass rigorous cold water regulations, making it suitable for any diving conditions.
Coming in DIN format, the first stage has two high pressure and four low pressure ports , is compatible with up to 40% EAN and is connected to the second stage by a lightweight and flexible maxweight hose. Fixed hose mounting is ideal for both backmount and sidemount configuration.
Hollis pride the 500se on it’s pneumatically balanced servo valve system whilst the mouthpiece has a patented design to improve comfort and reduce jaw fatigue. The second stage can be easily disassembled without the use of tools and underwater if necessary.
You can purge this regulator by pressing a small honeycomb pad at at the rear of the exhaust port. Some users have reported that this pad can be a little stiff to operate, but it’s easy to get used to!
Ultimately, the Hollis 500SE/DC7 is a very well made travel regulator that is both affordable and has many great features. It’s side exhaust secondary stage configuration is likely to be either a making or a breaking point, depending on what you’re into. The choice is yours!