Independent comparisons. We may earn from shop links. More info

DOM Diamant or ix Twido: which system you were quoted

Updated: October 2026

You have been quoted more than one DOM cylinder and the names do not describe the same key. DOM Diamant or ix Twido is that split. Diamant is the disc system in the three amazon.co.uk listings. ix Twido is a reversible dual-roller key, patent stated until 2036 on DOM-UK's page, and it is not in this set. rs Sirius is the name a UK stockist lists as TS 007 3-star, and it is not one of the three either. Prices are on the [DOM lock cylinder comparison](/hub/door-and-window-security/dom-lock-cylinder). Peter F. checked the manufacturer pages and those listings in October 2026. A qualifying purchase can earn a commission at no extra cost to you.

You have been quoted more than one DOM cylinder and the names do not describe the same key. DOM Diamant or ix Twido is that split. Diamant is the disc system in the three amazon.co.uk listings.

Our top picks

DOM DOM long-cam cylinder 30 x 40 mm

Best overall

DOM DOM long-cam cylinder 30 x 40 mm
6.6/10about £451.89
View offer
DOM DOM Diamant cylinder 30 x 30 mm

Best value

DOM DOM Diamant cylinder 30 x 30 mm
6.2/10about £431.56
View offer
DOM DOM Diamant nickel cylinder 30 x 30 mm

Rank 3

DOM DOM Diamant nickel cylinder 30 x 30 mm
4.8/10about £498.49
View offer
On this page
  1. 1.Diamant, the system in this comparison
  2. 2.ix Twido, a different key
  3. 3.Where rs Sirius fits
  4. 4.Which to ask a dealer for
  5. 5.Match the name to the job

Diamant, the system in this comparison

Diamant is DOM's disc cylinder, published with EN 1303:2015 code 160B0C6D and anti-snap marked No. Two amazon titles begin 333TDIA. The listing text does not spell that code out. The polished 30/30 at about £431.56 is the best value when the door measures 30/30. The brass long cam at about £451.89 is the top pick when that cam and the 30/40 split match. The nickel 30/30 at about £498.49 states 60 mm and does not number the keys. There is no ix Twido and no rs Sirius here. Diamond in the titles is Diamant, not Sold Secure Diamond.

ix Twido, a different key

ix Twido uses a reversible key and a dual-roller mechanism. DOM-UK states a patent until 2036, a registration card, EN 1303:2015 code 160B0C6B, and anti-snap as No. A blank from one system will not cut onto the other. If a dealer has quoted both, you are choosing a key family, not a finish. Diamant's published code ends in D. ix Twido's ends in B. On Hoppe's reading of BS EN 1303, D includes extraction resistance and B does not. Neither table says anti-snap Yes. This set has no ix Twido price. If that is the quote, buy it through the dealer who registers the card. A 30/30 Diamant does not become ix Twido because both are euro profile.
DOM DOM long-cam cylinder 30 x 40 mm

Testsieger

DOM DOM long-cam cylinder 30 x 40 mm
6.6/10about £451.89
View offer

Where rs Sirius fits

AC Leigh's DOM table marks ix Twido as not 3-star and rs Sirius as TS 007 3-star. That is a stockist's row, not an amazon.co.uk listing, and this page does not invent a price for it. Ask for rs Sirius when you want to stay with DOM and the requirement is the UK star. Diamant and ix Twido both have anti-snap marked No. The snap decision, including a 1-star cylinder plus a 2-star handle, stays on DOM cylinder vs TS 007. Ordering the about £431.56 Diamant because it is DOM does not put you on the rs Sirius row. Sigma Plus is a further name, the master-key workhorse, and a quote for it is a suite, not one of these three cylinders.

Which to ask a dealer for

Ask for Diamant, in the size you measured, when one door needs the disc key and you accept anti-snap marked No. The listings cover a polished 30/30, a nickel 30/30 and a long-cam 30/40. They do not cover 35/35, a thumbturn or British oval. The measurement order is on the DOM lock cylinder buying guide. Ask for ix Twido when the quote is the reversible key to 2036 and attack grade B is acceptable. You will not find it in this set. Ask for rs Sirius, or a cylinder that prints TS 007 or SS312, when the job is snap resistance. Several doors on one key need a master-key design. Three Diamant orders will not create that.

Match the name to the job

Diamant is the disc key you can order here, with anti-snap marked No. ix Twido is the reversible key to 2036, also marked anti-snap No, and it is not in this set. rs Sirius is the DOM name a UK stockist lists as TS 007 3-star. The top pick and the best value are both Diamant sizes.

Common questions

What is the mechanical difference between Diamant and ix Twido?
Diamant is the disc system, published with EN 1303 code 160B0C6D. ix Twido is the reversible dual-roller key, published with code 160B0C6B and a patent stated until 2036. The keys are not interchangeable. Both manufacturer pages mark anti-snap as No. In this amazon.co.uk set you can buy only the Diamant sizes. ix Twido stays a dealer quote.
Do either of them claim anti-snap?
No. DOM's Diamant table says anti-snap protection No. DOM-UK's ix Twido table says the same. A higher price, a nickel finish, or the word Diamond in a title does not overturn that line. The DOM family a UK ironmonger marks as TS 007 3-star is rs Sirius, which is not either of these two systems and not an ASIN here.
Can I buy ix Twido in this amazon.co.uk comparison?
No. The kept listings are three Diamant euro cylinders between about £431.56 and about £498.49. There is no ix Twido price in the set, and this page will not borrow one from another shop. If your quote is ix Twido, the registration card and the key family have to come from a dealer who supplies that system. A 30/30 Diamant of a similar length is a different key.
What does the security card change?
The card is what a dealer uses to cut a restricted DOM key. Without it, a high-street booth should not copy the key, and you cannot casually add a door. DOM describes a card for Diamant and a registration card for ix Twido. These listings do not say a card is in the box. Five keys are the keys in that parcel, not a later door on the same suite.
Will a euro Diamant replace a British oval DOM cylinder?
No. Euro and British oval are different profiles. The three listings are euro Diamant cylinders. An oval cylinder, even with DOM on the key, will not enter a euro hole, and a euro cylinder will not enter an oval hole. Match the profile first, then the measured split, then the system.

Related pages

Best DOM lock cylinder

DOM lock cylinder

What to check before you order a DOM lock cylinder

How to fit a euro cylinder without leaving it proud

DOM cylinder vs TS 007: skip Diamant for snap risk

Sources

Public UK and manufacturer sources, plus the amazon.co.uk listings B077Q4LF93, B08W4N7RSV and B077PSM71X. Figures are taken from those pages and from the digest. Checked for this comparison in October 2026.

  1. West Yorkshire Police, euro cylinder advice (retrieved October 2026)
  2. GOV.UK, Approved Document Q (retrieved October 2026)
  3. DOM Diamant double cylinder (retrieved October 2026)
  4. DOM ix Twido double cylinder, DOM-UK (retrieved October 2026)
  5. Hoppe, BS EN 1303 (retrieved October 2026)
  6. AC Leigh, DOM master-key cylinders (retrieved October 2026)
  7. Lock and Key, how to measure a euro cylinder (retrieved October 2026)
  8. amazon.co.uk listings B077Q4LF93, B08W4N7RSV and B077PSM71X (retrieved October 2026)