[Dynamo]

not sure witch are shown on redwolf, but they look like the 7MM type.
i got the PGC PRO-WIN 8mm (metalic grey color) and i love it to death.
there are a few things that you need to note down about it.
#1, you will need to grind down the inside of your M4/M16 body to make this mechbox fit.
#2 dont use the hop sleeve that comes with it. it seems that they made a mistake when they made the molds for it. the openning for the bb/nozzle is far too narrow and tight, the tappet plate spring will not be strong enough to puch a BB past the openning and into the hop chamber, causing back pressure in your cylender and slowing down your piston. if you fire in full auto with this hop sleeve, expect to strip the teeth off your piston (i went through 3 befor i figured out the problem). make sure you test any hop sleeve you plan to use by placing a BB on the openning, the sleeve should just be narrow enough to not let the BB fall through, but should be loose enough that a slight soft push will make the BB fall though.

#3 you are going to need to be carefull on how you shim up the gears, since the tolerances are so tight.
if you need help i can talk you through it onver PM.

other than that, this is one bad ass mechbox.
after i changed the hop sleeve i had no more issues at all with this mech box, this thing is a monster and now my VFC HK416 is a BB hose.