[spaghetti]

yes they do have a dual power switch, wich is useful to prevent damage to shafts and tips on shorter guns (from 40 to 85) if you shoot with lower power into holes or in narrow space between rocks, and with more power in open water. On longer guns it quite unnecessary because you will rarely (or maybe never) shoot into a hole with a long gun.
Mamba kit can be installed on any pneumatic. You can either buy a ready made mambized gun from the Mamba producer (Maorisub) or otherwise buy a mamba kit and install it by yourself on any gun.
Hope this helps.