Free Delivery on all orders over £99*

35mm Double Dry Lining Box - White PVC

£149
The RRP is the manufacturer's recommended retail price of the item.
Limited Stock
We are an Independent UK Company
Price match. Found it cheaper? Contact us
Trade Discount Available

Minimum order for this item is 10.

Description

The Knightsbridge SN8380 is a 35mm-deep double dry lining box moulded in white PVC, designed for flush-mounting electrical accessories into plasterboard and dry-lined cavity walls. The box measures 144mm wide by 83mm high externally, requiring a 133x73mm rectangular cut-out in the plasterboard, and provides a 35mm recessed depth behind the wall surface for wiring and accessory back boxes.

Used during first-fix electrical installation in new builds and renovations, the box accepts standard UK double-gang switches, sockets and faceplates once the plasterboard is in place. Red locking lugs on each side grip the reverse of the plasterboard when tightened, pulling the front flange tight to the wall surface and holding the box securely without needing screws into studs or additional fixings. Cable entry channels moulded into the top and bottom edges guide twin-and-earth or conduit into the box, and a 20mm knock-out at the rear accepts standard PVC conduit where needed.

The box is certified to BS 5733, the British Standard for general purpose thermoplastic enclosures for electrical accessories. The white PVC construction is non-conductive, resists impact during installation, and remains stable in typical domestic wall cavity temperatures. Knightsbridge supplies the box in shrink-sealed multipacks for trade and contractor use, with each unit carrying a 25-year warranty against manufacturing defects.

Specification
Height 83 mm
Width 144 mm
Recessed Depth 35 mm
Cut-out Box W/H/D 133x73 mm
Construction PVC
Finish White
Warranty 25
Downloads

Product Specification Sheet

Frequently Asked

What plasterboard thickness does this box suit?

The 35mm recessed depth suits standard 12.5mm plasterboard with 20-25mm of space behind for cable management. The locking lugs adjust to grip plasterboard between 9mm and 15mm thickness.

How is the box secured to the wall?

Red locking lugs on each side of the box screw inward to grip the reverse of the plasterboard. As they tighten, they pull the front flange of the box tight to the wall surface, holding it securely without needing screws into studs.

What accessories fit this box?

The box accepts any standard UK double-gang electrical accessory, including switches, sockets, dimmer modules, TV/data plates and USB charging sockets. The 133x73mm cut-out matches the standard double-gang footprint.

Is the 20mm knock-out pre-cut?

No. The knock-out at the rear is moulded into the PVC but remains intact until needed. It can be knocked out with a screwdriver or punch to accept 20mm PVC conduit where cable management requires it.

Shipping & Returns

Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

To arrange a return, call us on 020 8149 5199 or use our contact page.

See it lit, in person

Lighting looks different in a real room. Come and see our range at our showrooms in Birmingham, Hong Kong and Dubai, or talk to our design team wherever you are.

Niori lighting showroom trailer video with closeups of alabaster lighting

Why Niori

Over 20 years lighting homes worldwide

We are a specialist lighting and mirror retailer with showrooms in Birmingham, Hong Kong and Dubai, shipping to customers around the world. Our own design team is here to help, from first idea to final fitting.

Genuine products

An authorised stockist

Every product arrives brand new with the full manufacturer warranty. Found it cheaper elsewhere? Ask us about a price match.

Ordering with us

Free delivery over £99

Free delivery on orders over £99, in the UK and worldwide. Easy returns within 14 days, subject to our returns policy. Full manufacturer warranty included.

Design help

Not sure what you need?

Our design team can help you plan your lighting, share photos and videos of stock, and send samples worldwide. Book a showroom visit in Birmingham, Hong Kong or Dubai, or ask about our lighting design service.

You Might Also Like

Recommended For You

    Our Reviews

    From first click to final installation, our customers share how Niori lights up their spaces. Read their words and envision what’s possible for yours.

    Featured Projects

    Step into our portfolio and see how we transform homes, restaurants, and commercial spaces and more, worldwide. Click here for a closer look at our latest projects.

    Description

    The Knightsbridge SN8380 is a 35mm-deep double dry lining box moulded in white PVC, designed for flush-mounting electrical accessories into plasterboard and dry-lined cavity walls. The box measures 144mm wide by 83mm high externally, requiring a 133x73mm rectangular cut-out in the plasterboard, and provides a 35mm recessed depth behind the wall surface for wiring and accessory back boxes.

    Used during first-fix electrical installation in new builds and renovations, the box accepts standard UK double-gang switches, sockets and faceplates once the plasterboard is in place. Red locking lugs on each side grip the reverse of the plasterboard when tightened, pulling the front flange tight to the wall surface and holding the box securely without needing screws into studs or additional fixings. Cable entry channels moulded into the top and bottom edges guide twin-and-earth or conduit into the box, and a 20mm knock-out at the rear accepts standard PVC conduit where needed.

    The box is certified to BS 5733, the British Standard for general purpose thermoplastic enclosures for electrical accessories. The white PVC construction is non-conductive, resists impact during installation, and remains stable in typical domestic wall cavity temperatures. Knightsbridge supplies the box in shrink-sealed multipacks for trade and contractor use, with each unit carrying a 25-year warranty against manufacturing defects.

    Specification
    Height 83 mm
    Width 144 mm
    Recessed Depth 35 mm
    Cut-out Box W/H/D 133x73 mm
    Construction PVC
    Finish White
    Warranty 25
    Downloads

    Product Specification Sheet

    Frequently Asked

    What plasterboard thickness does this box suit?

    The 35mm recessed depth suits standard 12.5mm plasterboard with 20-25mm of space behind for cable management. The locking lugs adjust to grip plasterboard between 9mm and 15mm thickness.

    How is the box secured to the wall?

    Red locking lugs on each side of the box screw inward to grip the reverse of the plasterboard. As they tighten, they pull the front flange of the box tight to the wall surface, holding it securely without needing screws into studs.

    What accessories fit this box?

    The box accepts any standard UK double-gang electrical accessory, including switches, sockets, dimmer modules, TV/data plates and USB charging sockets. The 133x73mm cut-out matches the standard double-gang footprint.

    Is the 20mm knock-out pre-cut?

    No. The knock-out at the rear is moulded into the PVC but remains intact until needed. It can be knocked out with a screwdriver or punch to accept 20mm PVC conduit where cable management requires it.

    Shipping & Returns

    Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

    Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

    To arrange a return, call us on 020 8149 5199 or use our contact page.