CustomDUO modules

Petzl Duo LED upgrades 

Now Available

Latest v42 and Simple modules

CustomDUO LED Modules offer a significant upgrade for the Petzl Duo, replacing standard halogen bulbs and Petzl 5-14 LED clusters. CustomDUO modules are super reliable, and are very easy to fit in any original (pre 2018) Duo. 


The original Petzl Duo was produced from the late 1990s, principally as a helmet mounted caving lamp, before high power LEDs were widely available. The original Duo is without doubt the most widely used caving lamp. Other than the lack of light output and run time from the original bulbs, the Duo has proven extremely fit for purpose, with a comfortable 5m depth rating (will handle deeper !!). The Duo is suitably robust, typically withstanding a good few years of gnarly caving. It is easy to operate, having a caver friendly switch, is light weight and seats very well when helmet mounted. The battery box is easily opened, and is practical, using low cost, widely available AA batteries, which can withstand significant mistreatment when carrying spares. 


Since 2009, CustomDUO have manufactured a flexible range of LED modules to meet individual needs, including our best selling Omni modules (v42 and Simple).  CustomDUO modules are without doubt the brightest, and most effective retrofit LED upgrades available for the Duo, featuring practical power settings and user friendly operation, developed specifically for cavers. CustomDUO modules use the latest high power LEDs, significantly increasing light output and run time. Plenty of both for even the most pushing of caving trips.


Incidentally, the very first LED conversions for the Petzl Duo were constructed by innovative French cavers (not Petzl). These conversions incorporated a number of Nichia LEDs (5-8 from memory), and looked very similar to the Petzl modu'led 5 which they pre-dated. These were available from Expe in the Vercor as early as summer 2000, at least that is when we first recall seeing them.  


With a CustomDUO LED upgrade, (and decent quality low self discharge NiMh AA batteries), the original pre 2018 Petzl Duo has established itself as the outstanding low-mid cost helmet mounted caving lamp. A great choice for novices and serious expedition cavers alike. 


The original Petzl Duo modu'led 14 (14 LED module) offered light output of less than 70 lumens, at approx. 0.35 Amp (6 hours on set of AAs). Using the latest high power LEDs, CustomDUO modules can provide approx 170 lumens at this power level,  or a similar 70 lumen light output at around 0.15 Amp (16 hours on set of AAs).      

Availability of original pre 2018 Duo  

The original pre 2018 Duo is now discontinued. However, new stock is available and can still be purchased through specialist caving equipment retailers, and on line sources.  Due to it's upgradeable design and suitability for caving, astute retailers bagged surplus stock from Petzl, prior to launch of the industrial workplace orientated Duo models (Duo Z and Duo S). CustomDUO LED upgrade modules work with all original pre 2018 Petzl Duos.



Availability of original (pre 2018) Duo - upgradeable 


Guide to converting original headband Duo to helmet fixing 'fixo' specification


New Duo Z2 (from 2018) - not upgradeable