Acetech Predator MKII Tracer unit by X-Force Tactical 

There have been a heap of hks. Which one are you referring to

And yes a HK 416d is heaps better than a j8 they use a v2 gearbox not the older style gen8 but you can still get your j8 hitting hard with a few mods ,get a blue chihai motor a silver wiring kit with a 10a switch metal gear set a 14t metal rack piston and a decent alloy piston head with a green or brown oring a double oring cylinder head and nozzle set and a 1.4mm spring and metal spring retainer ,that's what mine is running in a singularity gearbox and i get 370fps all day with a 7.4mm 28.5cm alloy barrel and on 11.1v with the 18:1 gears it's reliable as ,it may not be the fastest but perfect for a beginner it was the first one i built like 2yrs ago and was perfect to learn how to tech man

They are here and online mate go to our website and check it out

If we got it in, it would retail around $180 They aren't cheap that's for sure.

Get a SLR man they are a solid blaster highly modifiable and look awesome ,the cqb has a little less fps due to the shorter barrel but easily fixed with a suppressor ,i have 2 short and 2 long and run 30cm stainless barrels in the cqb's one with a retro arms box and a Mk tactical v2 in the other and a ldx expert cnc gearbox in one of the longer but left the nylon box in the other longer one with minimal mods just to see how hard i can push it and it's happily doing up around the 380-400fps mark depending on gel's and that's with a shs m110 and a 40cm 7.2mm alloy barrel, don't get a scar the ugg boot buttstock looks terrible