QuadBox™ JMF

A robust segmental system

QuadBox™ JMF is a robust preformed underground access chamber system for use in many buried networks and utilities. QuadBox™ JMF system comprises 150mm sections which are stackable allowing variable chamber depths.

QuadBox™ JMF is available in 5 sizes including Footway 2, 4 and 6 and is Openreach approved. It is suitable for congested networks.

Trusted & Proven

QuadBox™ JMF is the original Openreach approved chamber and has been on the market since 2004, with ZERO reported product failures.


Features & Benefits



QuadBox™ JMF ring sections simply stack on top of each other to achieve the required depth. Sections feature a generous overlap and interlock for maximum integrity.

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QuadBox™ JMF is manufactured from HDPE, a material with excellent strength-to-weight properties. The structural foam twin-wall design reduces weight whilst yielding excellent vertical and sidewall strength.

QuadBox™ panels are safe for manual handling with no need for specialist equipment.

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Fast Install

QuadBox™ JMF has immediate load-bearing strength and offers single step installation, with no need for concrete backfill or raising frame. Installation can typically be completed in less than 1 hour.

40t top load


The QuadBox™ JMF range offers a maximum top load of 40t on the larger sizes. All sizes are suitable for installations in areas rated B125 under BS: EN 124: 1994. QuadBox™ is approved for Openreach installations in pedestrian areas that are rated B125.


Drop-in furniture

Specially designed furniture simply drops into the unique pocket designs in the chamber walls for a secure fit. No drilling, no fixings and no bolting required. Easy to install and to reconfigure. Range includes drop-in steps, wall brackets and Mobra. 


Easy Overbuild

Quadbox™ JMF lightweight stacking system is ideal for building over installed duct and reduces risk and disruption to the live network. Duct entries or arches are easily cut with a standard holesaw and the chamber HDPE material, being inert, does not produce any toxic dust.


Proven & Trusted

QuadBox™ JMF was originally designed for Telecom applications and was the original pre-formed chamber to be approved for use in the Openreach network. QuadBox™ JMF meets all Openreach quality requirements and reduces the number of checks to 8 versus 13 for brick and concrete, saving installation time..


Weather Resistant

QuadBox™ JMF HDPE material offers excellent weather and chemical resistance. QuadBox™ can be installed in all types of weather, unlike with concrete or brick-built chambers where conditions can stop work.


Sustainable & Safe

QuadBox™ JMF is manufactured from High Density Polyethylene (HDPE), up to 70% recycled. HDPE is non-polluting and fully recyclable. It is an inert material which does not produce any toxic dust and presents no health risk to operatives or members of the public. 




Type Openreach Ref. Length (mm)* Width (mm)* Height (mm) Max. Load Rating Product Code
FW1 N/A 300 300 150 B125 UY0000
FW1/EN1 N/A 600 450 150 B125 UY0001
FW2/EN2 JMF102 725 255 150 C250 UY0002
FW4/EN4 JMF104 915 445 150 D400 UY0003
FW6/EN6 JMF106 1310 610 150 D400 UY0004

*Clear openings

Related Products

QuadBox™ Step

Furniture & Accessories

Drop-in Steps and Cable Management, Mobra, Floors etc.

Composite Cover with Badge

Frames & Covers

The comprehensive range includes concrete infill, composite, ductile and recessed and steel covers.


Guides and handbooks (openreach.com)                                         

Furniture and accessories can be pre-fitted by Radius as required. We can also pre-drill duct entries to suit.


  • Duct Entries
  • Furniture
  • Floor


QuadBox™ JMF has been approved by Openreach since 2004




    Installation Guide