The Domus GTA-131 is a replacement diffuser for the CHESTERseries 165mm, aluminium frame, supplied on itsown.

Its title and its web address name two different parts

• The product is titled GTA-131 CHESTER SERIES DIFFUSER ONLY. Its handle the page’s own web address isgta-140-43mm-post-top-adaptor.
• A DIFFUSER PANEL AND A POST-TOP ADAPTOR ARE DIFFERENT OBJECTS DOING DIFFERENT JOBS. One is the panel a lantern glows through; the other is the fitting that joins a lamp head to apost.
• MEASURED: of 70 products carrying a GT or GTA code in both their title andtheir handle, 69 agree and 1 does not. This isit.
• THIS BREAKS THE RULE WE HAVE USED THROUGHOUT THIS PROGRAMME. Where aproduct record disagreed with its title, the title won on lamp bases, on voltages, on IP ratings. Here the title and the handle disagree with each other, so neither can arbitrate theother.
• SO WE WENT TO A THIRD SIGNAL, AND THE RECORD SUPPLIES ONE. It publishesdiameter = 165mm and material = Aluminium. A 43 mm POST-TOP ADAPTOR IS NOT 165 mm. The dimension matches a diffuserand rules out the adaptor.
• WE HAVE WRITTEN THIS PAGE AS THE CHESTER DIFFUSER, which the title and the dimensionagree on. The handle is wrong and a handle is the public URL, so this is a wronglink rather than only a wrong field. Confirm with us before ordering if you came herelooking for a post-top adaptor; you are on the wrong page and we will point you at the rightone.

What a diffuser-only part is for

• THIS IS A SPARE, AND ITS EXISTENCE IS THE POINT. A lantern’s diffuser isthe part that breaks hail, a stone from a mower, a ladder, UV over years while the casting,the lampholder and the wiring are all still sound.
• WITHOUT A SPARE PANEL, A CRACKED DIFFUSER MEANS REPLACING THE WHOLE FITTING and on an exterior lantern that means an electrician, not ahouseholder.
• WITH ONE, IT IS A TEN-MINUTE JOB. On a made-to-order range this mattersmore than usual, because the fitting itself is not held in stock replacing a whole lantern wouldmean the lead time as well as the cost.
• IT ALSO KEEPS A RUN MATCHED. Replacing one lantern in a row of six with anew one puts a fresh finish beside five weathered ones; replacing a panel doesnot.

Identify the series before ordering

• This panel suits the CHESTER series specifically. Domus’s traditional exterior ranges share a visual language but not theirparts.
• THE RELIABLE WAY TO IDENTIFY A FITTING IS THE GT CODE, not the shape. It is usually on the original invoice or on a label inside the fitting. Two lanterns that look alike across two ranges will not swap panels.
• IF YOU CANNOT FIND A CODE, MEASURE. This panel is165mm; a panel from an adjacent range will differ by enough to beobvious. Send us the measurement and a photograph and we will confirm before youorder.
• ORDER THE SET, NOT ONE PANEL, IF MORE THAN ONE HAS AGED. A new panelbeside three sun-yellowed ones is more conspicuous than four evenly agedones.

What this part does not have, and why that is correct

No voltage, no wattage, no IP rating, no lamp base. A DIFFUSER PANEL ISPASSIVE it has no electrical parts and should publish no electricalspecification. This one correctly publishes only a diameter, a material and awarranty. That is worth stating because it is unusual: 83 of 104passive parts in this catalogue diffusers, bases, adaptors, brackets and spares do carry anelectrical field they cannot have. An absent specification on a passive part is not agap; it is the right answer.

Made to order

Allow up to 10 business days for production. Worth planning for on a sparepart a broken diffuser is usually discovered when you want it fixed, not ten daysbeforehand. On a property with several of these lanterns, keeping one spare panel on ashelf turns a ten-day wait into an afternoon.

What is published

Where it works

• Repairing a CHESTER lantern not replacing it.
• Keeping a run matched a panel, not a new fitting.
• As a shelf spare it removes the ten-day wait.
• Not ordered on shape alone confirm the GT code.
• Not if you wanted a post-top adaptor ask us.

Specifying it

Replacement diffuser panel for the CHESTER series. 165mm, aluminium. Supplied on its own.No electrical parts. Made to order, up to 10 business days. 1-year warranty. THIS PAGE’S TITLE AND ITS WEB ADDRESS NAME DIFFERENT PARTS GTA-131 Chester diffuser againstGTA-140 43 mm post-top adaptor, which are different objects doing different jobs. Of 70 products carrying aGT or GTA code in both their title and their handle, 69 agree and this one does not. That breaks the rulewe have used throughout this programme, where the title arbitrates a disagreeing record here the titleand the handle disagree with each other. SO WE WENT TO A THIRD SIGNAL: the record publishes 165 mm, anda 43 mm post-top adaptor is not 165 mm. The title is right, the handle is wrong, and a handle is thepublic URL. If you came here for a post-top adaptor, ask us you are on the wrong page.

Supplied and supported by Lights For You.

Questions

Is this a diffuser or a post-top adaptor?

A diffuser. Its title says GTA-131 Chester Series Diffuser Only and its handle the page’s web address says GTA-140 43mm post-top adaptor, and those are different objects. We went to a third signal to settle it: the record publishes 165mm and aluminium, and a 43mm post-top adaptor is not 165mm. The title is right and the handle is wrong.

How did you decide which to trust?

Normally the title arbitrates throughout this programme, where a product record disagreed with its title on a lamp base, a voltage or an IP rating, the title won. Here the title and the handle disagree with each other, so neither can arbitrate the other and a third signal was needed. The published diameter supplied it.

Is that error common?

No. Of 70 products carrying a GT or GTA code in both their title and their handle, 69 agree and 1 does not. This is the one. It matters more than a typical field error because a handle is the public URL, so it is a wrong link rather than only a wrong field.

Why buy a diffuser on its own?

Because it is the part that breaks. Hail, a stone from a mower, a ladder or UV over years will crack or cloud a diffuser while the casting, the lampholder and the wiring are all still sound. Without a spare panel a cracked diffuser means replacing the whole fitting and on an exterior lantern that means an electrician rather than a householder. With one it is a ten-minute job.

Does it matter that the range is made to order?

It makes the spare more valuable. The fitting itself is not held in stock, so replacing a whole lantern would mean the lead time as well as the cost. It also keeps a run matched: replacing one lantern in a row of six puts a fresh finish beside five weathered ones, where replacing a panel does not.

How do I know it fits my lantern?

Identify the fitting by its GT code, not by its shape Domus’s traditional exterior ranges share a visual language but not their parts, and two lanterns that look alike across two ranges will not swap panels. The code is usually on the original invoice or on a label inside the fitting. If you cannot find one, measure: this panel is 165mm, and a panel from an adjacent range will differ by enough to be obvious. Send us the measurement and a photograph and we will confirm.

Why does this page list no voltage or IP rating?

Because a diffuser panel is passive it has no electrical parts and should publish no electrical specification. This one correctly publishes only a diameter, a material and a warranty. That is worth stating because it is unusual here: 83 of 104 passive parts in this catalogue do carry an electrical field they cannot have.