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LB21 - 10 inch uPVC Letterbox

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  • 10 inch upvc letterbox will fit most upvc and timber doors!

  • Weatherproof and non-rattle as standard.
  • 265mm width x 70mm height with two lug fixings at 235mm centres.
  • Watch the product features video of a 10 inch standard upvc door letterbox.
  • How to fit a upvc letterbox video.
  • Typical replacement upvc letterbox questions and answers.
  • We supply two standard size screws (63mm long) to suit a door thickness of 52-57mm. Other screw lengths can be ordered from here: Letterbox screws. Correct screw sizes must be used for your 10 inch upvc letterbox door thickness.
  • Telescopic sleeve for varying door thicknesses! 
  • Supplied as an inner and outer plate set.
  • Includes a brush seal and further weather stripping to seal the letter plates.
  • External letterplate opens to 145 degrees and is sprung loaded!
  • Not suitable for coastal designated areas. Please contact for more details.


How To Replace and Measure A 10 Inch upvc letterbox


If you are trying to measure through the aperture of the letterbox sleeve to avoid taking the unit off the door then compare to these sizes. Postal slot on your existing letterbox needs to be 215mm x 37mm with fixing centres of 235mm. We still recommend taking the letterbox off the door and measuring against the diagram in the section above (under the main picture). The overall sizes of the upvc letterbox is 265mm x 70mm (close to 10 inch x 3 inch). Here is a short 2 minute video on how to fit a upvc letterbox which includes the measuring part.


This model is one of the oldest and best 10 inch upvc letterbox around in the UK. Having been sold now for around 20 years these letterboxes for upvc doors are so simple yet effective, aesthetically pleasing and boy they do the job! An integrated brush seal is set within the sleeve and this helps with draughts. There is also a rubber gasket encased within the plastic back box so that when the letterbox closes it seals against the plastic. Furthermore the springs are strong and the flap will make a resounding closure to ensure that the elements of wind and rain will not lift the 10 inch plate for water ingress. Of course they are there for a purpose and this 10 inch letterbox will allow full A4 post to be delivered without bending.


Available in a white or black surround (plastic) these letterboxes have an aluminium letterplate which is finished to a high standard via anodising or powder coated paint.


Fixing is achieved by two self-tapping screws that pull the two halves of the letterbox together and effectively clamp it to the door (screws on the inside under the flap). If you are replacing a upvc letterbox with 4 screws each side that are face fixed into the door then this model can be altered if you have a bit of diy tendency to your name! There are 4 moulded positions each side for you to pierce through with a drill and then just slice the two centre lugs of with a sharp chisel.


A few important notes about this 10 inch uPVC letterbox:

Replacement of this 10 inch letterbox requires that you check the inner sleeve size as this has to go through the existing aperture in your door.


Customers please note that the silver polished colour now replaces the polished chrome for longevity.


Cleaning the letter plate surfaces should only require a periodic wipe with a dry cloth. The use of chemical cleaners or agents should be avoided. 

Not suitable for coastal designated areas. Please contact for more details.


Remember to check the screw length but don't panic as they use No.8 woodscrews to self tap the plastic lugs when first used and you can get these anywhere (probably in your toolbox).

Christmas Delivery: Our dispatch dates continue upto 2pm on Thursday 23rd December. We will also be dispatching on Thursday 30th December to help with orders placed through Xmas, and then from Tuesday 4th January 2022.

European Deliveries are currently suspended.

The following special offers are available to you when you buy the 10 inch uPVC Letterbox. The discount for the special offer will show in the cart if both the 10 inch uPVC Letterbox and the special offer product are added.

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