25XR AST 1st Stage

Product No: 416400


The 25XR first stage is extremely reliable and perfectly sealed thanks to the standard CWD kit. Perfect for any type of configuration with pre-oriented HP outputs.

Product Information


The 25XR AST first stage was created to mainly meet the needs of divers using the double tank or to be mounted on a stage. The first stage immediately strikes any technical diver's eye, due to the presence of preoriented Lp and HP outputs positioned on one side only. In fact, this model was created to have an assigned position. The hose exits are positioned so that they fall behind the diver during assembly. This feature makes it ideal for cave diving or in environments with limited passages.

The key features of the 25XR AST first stage are:

• All metal body
• Nickel and chrome plated marine brass
• Solid and compact one piece body
• Balanced diaphragm - DFC
• New ACT valve - Advanced Coating Technology
• Dry CWD kit for cold water
• DIN only
• Use with trimix, eliox, elitrox up to 150m
• 2 low pressure outlets (3/8 "UNF) all angled downwards
• 1 high pressure outlet (IPD: Intelligent Port Design - design with smart outlets) enhanced (7/16" unf)
• Extreme reliability - maximum safety
• Optimized breathing comfort
• Extreme depth, demanding dives and mixtures (helium, o2, nitrogen)
• Perfect hose positioning - no unnecessary output - ideal hose layout to avoid entanglement
• To be used with double tank but equally suitable for the configuration single tank or stage
• IPD: Intelligent Port Design
• Double configuration: satisfies all educational agencies from RSTC to different all technical uses, including cave diving
• Minimizes the risk of getting in the way, no kinking of the hoses and easy access to the taps knobs
• 2 watertight systems: isolate the main spring and valve from possible ice formation and/or contamination
• Resistant to cold water
• AST - Auto Sealing Technology. Keeps the first stage dry. Reliability without any compromises. The system is automatically activated by air. Tested with oxygen and low temperatures in demanding environments. Patented system


High pressure ports:
1 (7/16” UNF)
Low pressure ports:
2 (3/8” UNF)

Delivery & Returns


Online purchases on mares.com are enabled for Italy, France, Spain, Germany and Austria. Some products from the catalogue are only available to purchase at an authorised Mares Dealer.

Products shipped in Italy are entrusted to Bartolini couriers. Products shipped in France, Spain Germany and Austria are entrusted to DHL couriers.

Delivery times are 3-5 working days.



If you are not satisfied with your order, you can return it quickly and easily.

You can decide to return any products purchased on mares.com within 30 days of delivery. To return items, use the same box they were received in, complete the returns label found here with shipping details and attach it to the box. Remember to insert the delivery number found on page 1 of the delivery documents.


To allow you greater freedom, we have not chosen a courier service with which you need to return the package, you are free to choose your preferred service provider.

Please remember that shipping costs are your responsibility.


At the moment, we cannot offer exchanges on our products. If you would like a different size, please return the article for a refund and purchase a new size. If you still have any doubts, you can write us an email at shop@mares.com, our Customer Service team will be happy to help.