I have the dark greay one as well although it wont work in this naltitude for some weird reason, 4200 meters is quite high.
Anyhoo one thing that really important to do before you refilol is blled the btank. Take a nail or sharp metal small point and rlelease all the left over pressure in the tank prior to refilling.
They sell tools for this at head shops sometimes but a nail works good, just be careful cuz its ice cold gas coming out.
The n refil until it just stops filling. No need to count it will stop whe its full.
I am not gonna lie, shits gonna get weird!Troubles Breaking Through? Click here.
The Art of Changa. making the perfect blend.