CustomDUO design and manufacture retro-fit LED modules that significantly upgrade the original Petzl Duo, almost certainly the most widely used caving light globally.  


Established in 1995 (as LED-Techno) Customduo developed the earliest white LED caving lights, in the form of LED upgrades for mining lamps including helmet mounted battery packs, commercially available (1997) from caving retailers in the UK and other countries. We still manufacture CustomPITLAMP modules for mining lamps, albeit difficult to recognise from our original upgrades.


Based in the UK, Customduo also design and manufacture a range of other specialist underground lighting related products, including Rude Nora and Filthy Edna ............... the Little Monkey caving lights

v42 module - Customer review  


LED Module for Petzl Duo



7.4V USB charger for SCURION tm 


Extremely useful / essential bit of kit for caving lights using 7.4v li-ion battery packs, such as Scurion tm. Easily adapted to older 7.4v systems such as Stenlight etc.


Find it here



Converting Petzl Duo to Li-ion Batteries 


With an increasing number of folk doing a 3.7v li-ion battery conversion on Petzl Duo, we thought we ought to pull up our big girl pants and have a go at it!


Read more here

v42 & Simple LED modules for Petzl Duo    


New - version r02 landing soon (Nov 2020)



3.7V li-ion USB chargers (new)


Full range of USB chargers for 3.7v li-ion battery arrangements. USB-A, micro USB and USB-C. Perfect for very latest caving light tech, such as Rude Nora lamps and Filthy Edna lamps, or other 3.7v li-ion charging requirements.      


Find it here