Despite what you can see in the picture on the left (and on the manufacturer's website) Myo series was quietly redesigned in 2010. According to the markings on the housing since June 2010, Myo series was manufactured with a new type of power cord and cable guard on the connection with the headlamp body. In theory, this should eliminate the problem of short circuits and failures tormenting this series ...
This is the new version of the Myo RXP - Myo XP is the same only in its own gray / green color.
The new cable is round and is considerably more flexible than previously used.
Headlamp in the new version are available for some time in the most of stores - so that if you bought it online and get the old version send it back and buy it elsewhere..
Regarding the lumen output, nothing has changed, Petzl declares 140 lumens on led for RXP model on high and after checking it looks like their numbers much the real output .
The measurement was made using a new set of batteries and the headlamp was equipped with the SSC P4 U2 SW0H led. There is no room for excessive optimism, in Petzl they know exactly what they are selling… According to the manual, Myo RXP runs on high mode only for about 50 minutes, that's why on the rechargeables after a week or two after charging you will get only 105 lumens on high…