Tokyo Marui's replica of the FN P90.
It has a stock red dot sight, which I honestly didn't expect to be any good, but it does it's job as good as my other red dot sight, although the field of view is small.
I bought it second hand from a guy who's had it for years, and obviously he didn't care much for maintaining it. The parts were worn down and covered in grease full of dirt.
So I bought a 120% full tune up kit from Systema, cleaned the dirty barrel, and now it's up and running smoothly.
The P90 is normally shorter than the one in the picture, because I've added an extended rubber butt plate. One, because the previous owner had lost the original butt plate, and two, because this gives you space enough to fit a larger battery, which is always good.
Compared to it's rival, the TM MP7A1, it feels a lot heavier, and you don't have the same freedom of movement with it as you have with the MP7A1. The accuracy and power is slightly better than my MP7 though.