Echo1 Complete 8mm Metal Gearbox for M4 / M16 Series Airsoft AEG Rifles (Wiring: Rear)

"Will this work with my scar

"Holy crap. This thing works a miracle WITHOUT upgrades. I slapped this into my gun and holy crap. This was nuts. Of course I've done some minor upgrades like new gears for more torque and a stronger spring, other than that, its all original. Amazing gearbox.

"Great drop in part, especially with it being the steel gears, 8mm bearings, it came with a different non ported cylinder than my original, have yet to test it out on the course, but other than that was a straightforward easy install.

"This gearbox is awful!

The compression unit requires replacement right out of the box so I had to get a new piston and O ring to make it ever work properly.

This page fails to tell you that it does not have connectors and have to by them separately and buy wires to add the connectors yourself. Not too bad if you want a specific type but would be nice if there was a label or better pictures for this gear box to show you that.

Fire Selector on this is completely busted so it only full auto at all times, even set to "safety" so can't place a finger on the trigger.

Finally the gears are all messed up and don't even rotate and requires complete disassembly of the gearbox to address the issue. For me the only way to address the issue is replace all the internal components of the gearbox and at that rate, I might just buy an entirely new gearbox.

This really should be placed in the "Gearbox Graveyard" section because that all that it is. Heck it would sell more if it was just the gearbox without the internals alone since even the parts that are used to build it are second hand junk and are not even worth removing out of this gearbox and moved into another.

Not worth it's price range, not even close. The quality I got from this is worth $15 and that is just pushing it.