How Spare Air Works

Spare Air is a compact, self-contained emergency backup for your primary SCUBA air supply. Its always-on regulator delivers air when you breathe.

Spare Air components labeled A through H — Identify each component on your Spare Air.

Know your equipment

Part	What it does
A · Mouthpiece	Silicone mouthpiece.
B · Purge button	Clears the regulator and empties the cylinder.
C · Serial number	Identifies your unit for service.
D · Regulator	Always-on, breathe-on-demand, balanced single-stage design. Internal service requires a certified repair technician.
E · Refill port & cap	Connects to the appropriate refill adapter. The cap protects the port.
F · Pressure indicator	The standard pin is flush at 3000 psi and recessed when refilling is needed. An optional dial gauge displays PSI and BAR.
G · Cylinder	3000 psi aluminum cylinder. DOT/TC and ISO-marked cylinders for EU countries are available.
H · VIP sticker	Shows the month and year of the last cylinder visual inspection.

Diver underwater with Spare Air mounted on BC — Mount Spare Air where you can reach and deploy it.

Ready before the dive

Read the owner’s manual, check that the cylinder is full, and practice deploying Spare Air in controlled conditions. Follow your SCUBA training and never hold your breath during ascent.

Using Spare Air Mounting guide

Download the owner’s manual (PDF)

Air capacity & duration

Available air depends on cylinder size, depth, breathing rate and activity. These published surface-breath figures compare the current diving models; they are not a guaranteed number of minutes or an ascent plan.

Diving model	Air capacity	Approximate surface breaths*
300 / 300-N	3 cu ft · 85 liters	57
600 / 600-N	6 cu ft · 170 liters	114

*Based on 1.5 liters per breath at the surface and a full cylinder. Breathing at depth consumes more air; exertion and stress also reduce duration. Nitrox models have the same air capacity as their corresponding standard models.

Compare current models

Common questions

What maintenance does Spare Air require?

Rinse with fresh water after use, dry, and store full. We recommend annual regulator servicing and an annual internal and external visual inspection of the cylinder. DOT 3AL cylinders require hydrostatic testing every five years; requirements can differ by cylinder markings and location.

Frequent use, training and chlorinated pool water may require more frequent service. See repair and service information.

Can I service Spare Air myself?

Certain external replacement parts, such as the mouthpiece and refill port cap, are available to customers. Internal regulator repairs require a certified repair technician. If your unit is damaged, leaking or missing parts, have it examined before use.

Shop replacement parts · Arrange service · Download the Repair / Trade-in Form

Can I take Spare Air on an airplane?

Yes! Empty Spare Air units are permitted in carry-on or checked baggage when completely depressurized and the regulator is removed. The cylinder must be open for visual inspection. Airline and destination restrictions may apply.

See the travel guide.

How do I refill Spare Air?

Use the appropriate adapter to fill from a SCUBA cylinder, dive-shop compressor, suitable portable compressor, or high-pressure hand pump. Compare the four refill methods.

Watch: emergency-ascent demonstration

A demonstration is not a promise of air duration. Read the manual and practice with your equipment before use.