Just received my G&G tracer unit and couldn't be happier. Waited impatiently at work for it to charge then rolled a few rounds down it under a desk to make sure it functioned. I'd seen a few videos of this in action and wasn't sure if it came across very well on some of them. I then sat at home, waiting for it to get dark then nipped out into the garden to let a few off. Amazing! Looks really effective like anti-aircraft rounds zipping about. You lose sight of them at about 100ft but that's plenty if you ask me.
Not too heavy either and easily screws on to the barrel in place of the flash hider. Mine is fitted to a 7" warthog.
Well worth every penny :-)