Solid gun. Has outperformed any other gun i have had yet. Comes with 500mm barrel, will fit a 510mm though. Gearbox is for all practical purposes lipoly ready, albeit a low lipoly (8.4 v or there abouts). Comes with low-res silver wiring, and automotive fuse standard. Blowback system is practical, easy to disable, and looks nice. Adds a bit of recoil, and the vibration may affect accuracy a bit. Gearbox comes standard with heat vents near the back along the spring guide, and is one of a kind. It's tough to find a replacement, you have to buy a whole new gun to get another one. Internals are very nice. Cylinder looks like a stainless steel type 0, spring is about a 120 or 130, giving it about 400 fps. gears seem tough enough, and piston may need to be replaced wit ha stronger one, it felt skimpy and cheap. Be warned, it has a square notch cut out at the top and back of it for the blowback catch to function. A new piston with out that notch will not work with the blowback enabled. Blowback has two ways to disable: take out the screws connecting the rod to the external bolt, or disassemble the gearbox and remove system entirely. The system is composed of 2 parts in all, fairly easy to take out. Comes standard with metal air nozzle (I had to buy a second one to fix the gearbox itself), both of them came with metal air nozzles. Very nice. Motor is a bit slow for ROF, but running a 9.6 v in it can cure that to some extent. hopup unit is poor, plastic and cheap. Recommend new metal one, and new bucking as well. Actually, get a new hopup all together (Madbull will work fine I should think). Externals are nice and sturdy, stock is a bit wobbly (it's a problem with all of them, but not a big one) and markings are awesome (they messed up the caliber though.) External dis-assembly is tricky though. Search up the Echo 1 dis-assembly video before you do it yourself.
That's that. Good gun. Very reliable.