Spot-beam LED units for Petzl Duo headlamps.
Using a modern high-efficiency LED with great spot beam optic, the Solo gives a far better spot beam for your Duo than either the
regular halogen bulb or the common LED-based screw-in replacement bulbs.
The power draw of the standard Solo is similar to the common screw-in LED bulb, and
around half that of the regular halogen bulb, but
but with its powerful output and good beamshape, the Solo completely outclasses both.
Compared to the common LED bulb at tightest focus, the Solo spot beam is both more intense and significantly wider, and outside the spot beam area, there is much-improved 'spill' light, so as well as being a good spotting light, the beam is also much more usable for general caving.
With efficient voltage-converting electronics, output regulation is rock-solid from start to finish, as can be seen
The Solo is electronically protected against reverse polarity, so fitting one into an older
headset with 'incorrect' polarity or fitting batteries incorrectly will not harm it.
A standard Solo has an LED output of ~120 lumens, but alternative power outputs are available on request for people with different power consumption requirements.