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 & Simple LED modules for Petzl Duo    


New - version r02  (Nov 2020)

(New 2024)  Rude Nora and Scurion li-ion USB-C chargers  


'Switch mode' USB-C smart chargers. For 3.7v parallel li-ion battery arrangements, speciifcally Rude Nora and Filthy Edna caving lamps.


Also available, 7.4v version for 2s series wired li-ion battery packs, suitable for Scurion caving lamps.  


Find it here

v42 module - Customer review  


LED Module for Petzl Duo

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