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Flush or surface mount PIR sensor

Updated: 23 October 2026

The ceiling in front of you is solid, or the void above the plasterboard is too shallow. A flush PIR sensor needs both a hole and that void. A surface body avoids the cut. In this amazon.co.uk set, only one listing states both jobs. This page is that decision, not a ranking of every flush model. The comparison is on the [Flush PIR sensor](/hub/electronic-surveillance/flush-pir-sensor) page. The dual-mount row is about £15.99. Peter F., DIY and tools editor, updated this on 20 October 2026 from the saved listing. The adapter was not fitted in a lab. A qualifying purchase can earn a commission at no extra cost to you.

The ceiling in front of you is solid, or the void above the plasterboard is too shallow. A flush PIR sensor needs both a hole and that void. A surface body avoids the cut.

Our top picks

SEBSON SEBSON IR_ES_A flush

Best overall

SEBSON SEBSON IR_ES_A flush
9.4/10about £13.99
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SEBSON SEBSON IR_ES_D flush or surface

Alternative

SEBSON SEBSON IR_ES_D flush or surface
9.0/10about £15.99
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Sensky Sensky BS041 recessed

Best value

Sensky Sensky BS041 recessed
9.0/10about £12.99
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On this page
  1. 1.What the ceiling lets you do
  2. 2.IR_ES_D as the hinge
  3. 3.What reviewers report
  4. 4.When to leave this listing

What the ceiling lets you do

Flush is the right shape when you have a void deep enough for the body and a hole you can match to the listing. Surface is the right shape when the ceiling is concrete, when you will not cut plasterboard, or when a joist sits where the light needs to be. A Timeguard surface unit and a Danlers CESR are context for solid ceilings, not extra rows here. If there is no void, there is no flush fit. SEBSON IR_ES_D (B07ZDFKGV8) is the only kept listing that states both flush and surface, with a screw-on adapter in the box. Everything else here is flush-only. A surface-only SEBSON was left out on purpose. The adapter does not change the IP rating, and it does not invent a cut-out the listing left blank.

IR_ES_D as the hinge

IR_ES_D is about £15.99, with 4.3 from 1,508 amazon.co.uk reviews. The saved row says indoor, and the IP rating is not stated. An older title has said IP20. That is not the cell this comparison uses, so this page does not call the unit IP20. The body is Ø79 x 40 mm. Range is 8 m, LED load is 600 W, and the delay runs from 10 seconds to 30 minutes. The cut-out and the voltage are not stated. The frequency cell prints 60 Hz, which is not UK 50 Hz mains.
SEBSON SEBSON IR_ES_A flush

Testsieger

SEBSON SEBSON IR_ES_A flush
9.4/10about £13.99
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What reviewers report

One review said the springs did not hold the flush fit. Another said the flush adapter leaves almost no room for the conductors. A garage install used the surface adapter, and a shallow ceiling was cited for the 40 mm body. One reviewer measured 5–7 W on standby. A 0.5 W figure they quoted is not a saved field. The cable-space complaint is the practical limit.

When to leave this listing

Choose the surface adapter on IR_ES_D when there is no safe void. Choose a flush listing with a printed hole when the void is deep enough and you want the body hidden. Do not choose IR_ES_D for a stated IP rating or a stated cut-out. Both cells are blank. IR_ES_E prints Ø63–66 mm and is not a surface unit. Sensky BS041 prints 65–70 mm and is not a surface unit. Hole sizes are on the flush PIR sensor buying guide. A hallway or a doorway is on the best flush PIR sensor page. Cutting a stated hole is on how to install a flush PIR sensor. A Knightsbridge dual-mount at another retailer is a different product. Screwing an adapter to the ceiling does not add a water digit.

Common questions

Can I fit a flush PIR on a solid ceiling?
No. A flush body needs a void behind the plasterboard or the board you are cutting. A solid ceiling has nowhere for that body or for the cable loop. You use a surface sensor instead. In this set, that stated option is the screw-on adapter on IR_ES_D, not a hole you force into concrete.
Which listing in this set does both flush and surface?
SEBSON IR_ES_D, B07ZDFKGV8, at about £15.99, with 4.3 from 1,508 reviews. The box includes a screw-on surface adapter. The other kept rows are flush only. The saved row leaves the IP rating and the cut-out blank. A surface-only SEBSON was left out of this category.
How deep is IR_ES_D, and how big is the hole if I do recess it?
The saved size is Ø79 x 40 mm and 81 g. Forty millimetres is a shallow body, which is why some reviews use it in a thin ceiling. The cut-out is not stated. Do not borrow 63 mm from IR_ES_E or 73 mm from a trade sheet and call it this listing’s hole.
What do reviewers say about the springs and the cable space?
One review said the springs did not hold. Another said the flush adapter leaves almost no room for conductors, and called the terminals tiny. A garage install used the surface adapter instead. Treat those as buyer reports on this ASIN, not as a lab measurement of every ceiling.
Is a surface PIR the same product as a flush PIR with an adapter?
On IR_ES_D, the listing sells one detector and says you can mount it flush or on the surface with the adapter. A surface-only sensor is a different product and was left out of this category. Trade pairs, such as a Danlers flush unit and a Danlers surface unit, are two models, not this adapter.
Does surface mounting change the IP rating?
No. The IP cell for IR_ES_D is blank. An older title line that said IP20 is not the cell this comparison uses. Screwing the adapter to the ceiling does not add a water digit. Bathroom zones still apply if the ceiling is over a bath or shower.
When is cutting the hole still the better choice?
When the void is deep enough for the body and the cables, and a listing prints the hole you will cut. IR_ES_E states Ø63–66 mm. Sensky states 65–70 mm. IR_ES_D does not state a cut-out, and reviews say the flush adapter is tight for cable. Hide the sensor with a printed-hole flush unit, and keep IR_ES_D for the ceiling you cannot cut.

Related pages

PIR sensor bathroom zones

Flush PIR sensor

Best flush PIR sensor for one dry-room job in the UK

A flush PIR sensor: the figures that decide the fit

How to install a flush PIR sensor in your UK ceiling

Sources

Public UK sources from the research digest. Shelf prices, stars and review counts are the figures stored with these nine amazon.co.uk listings. No laboratory test was carried out. October 2026.

  1. Approved Document P, 2013 (retrieved 22 October 2026)
  2. GOV.UK: building work, replacements and repairs (retrieved 22 October 2026)
  3. GOV.UK: Electrical Equipment (Safety) Regulations 2016 (retrieved 22 October 2026)
  4. SELECT bathroom zones guide, 2022 (retrieved 22 October 2026)
  5. IET: section 701, locations containing a bath or shower (retrieved 22 October 2026)
  6. Danlers CEFL PIR user guide (retrieved 22 October 2026)
  7. Autenco flush PIR data sheet (retrieved 22 October 2026)
  8. Lighting Industry Association: inrush currents (retrieved 22 October 2026)