12L Eurocylinder Twinset - Flat Bottom (Concave)
Dispatched 1 to 2 Days
Fully assembled flat bottom O2 clean 12L Euro Twinset stands up on their own and come with high-quality BtS manifold and marine grade stainless steel twinning bands.
UK Mainland Delivery Options
12L Eurocylinder Twinset - Flat Bottom (Concave)
O2 clean 12L Eurocylinder Twinset with Flat Bottom (Concave), high-quality BtS stainless steel twinning bands, and manifold with an isolator.
These flat-bottom manifolded doubles are our best sellers. With a working pressure of 232 bar, the twinset stands independently, thanks to a concave bottom. They are assembled with robust 2-inch wide marine-grade stainless steel BtS twinning bands featuring Delrin thumbwheels. The dependable barrel-type reliable BtS manifold and valves complement the sets.
All our twinsets come with O2 clean VIP stickers and decals as of the month of purchase. All sets are tested to working pressure and depressurised before shipping by courier allowing you to adjust the centre manifold before your first fill.
UK Delivery Options
Because Twinsets are heavy, oversized and fragile, they can get damaged in transit when fully assembled. For UK mainland customers, we offer three options:
COLLECTION: Collect from our Portland store.
SELF-ASSEMBLY: Isolator Bar and Twinning Bands are separated from the cylinders. (3 boxes)
FULLY ASSEMBLED: The set is sent fully assembled in one large and heavy box. Couriers find it hard to handle, and occasionally, sets get misaligned. If this happens, only the manifold needs to be replaced. We will arrange for a new manifold to be sent to you for you to assemble. The damaged manifold will be collected from you at our cost.

12L Eurocylinder Twinset specification
- O2 clean for 15 months from the date of purchase
- Working Pressure: 232 bar
- Cylinder diameter: 171mm
- Cylinder length without valve: 69cm
- Average cylinder weight without valve: 14.9kg
- Barrel type BtS Manifold (M25)
- Marine grade stainless steel BtS Bands
Ordering from outside of the UK mainland?
Due to shipping costs, Twinsets do not qualify for our standard shipping fees. If you want these delivered outside the UK mainland, contact us using our ONLINE CONTACT FORM with your delivery address. We will then be able to provide you with a non-binding shipping quote.

New to manifolds and twinsets? FAQ: See how it works
When the manifold centre valve is in the “open” position, both cylinders will be equalised, acting as a larger gas supply whether the diver is breathing off the primary or backup regulator.
As long as the left and right-hand valves remain open, each regulator will provide access to what is now a single gas supply.
When the manifold valve is in the “closed” position, the cylinders will be isolated from one another and run independently, effectively creating two separate gas supplies accessed respectively by the backup or primary regulator.
The main advantage of the twinset manifold is that it provides redundancy in case of failure involving either side. Closing the manifold valve will effectively isolate one cylinder (one side) from the other, providing the diver with the remaining gas from the valve on the functioning side.
If the manifold is in an open position but either the left or right-hand cylinder valve is closed, the regulator connected to that valve (post) will not allow access to the gas in any of the cylinders.
That post's valve will have shut down gas flow to the regulator attached to it, even if the manifold valve itself is open. However, the regulator on the open post will still have access to the total gas supply (both cylinders) unless the manifold is closed.

SHIPPING & RATES
You can find our current shipping rates in our Shipping Policy & Rates.
We aim to dispatch all in-stock items within 2 working days. The Dispatch Days listed in our product listings refer to working days.
We will inform you of approximate delivery times should any item on your order be out of stock or on supplier backorder due to current manufacturing or transport delays caused by global shortages and/or impeded production.
INTERNATIONAL EXCEPTIONS
Please contact us in advance for a shipping quote before placing an international order for weights, cylinders (excluding suit inflation bottles), and Suex scooters. These products are not included in our global max-capped shipping rates.
They are only shipped outside the UK mainland after the freight cost is calculated based on the parcel's total weight, dimensions, delivery location, and the courier service used.
RETURNS & REFUNDS
We offer a 30-day return for any product sold under our Returns & Refunds Policy.
Please email us at sales@dirdirect.com with your order number to receive our Returns Authorisation Form and instructions.
Return postages are at your own cost and our outbound shipping costs (if items are sold with integrated basic shipping charges i.e. Free shipping for orders above certain amount) the current UK shipping rate will be deducted from any UK mainland refund unless linked to a fault/defect claim.































