Not very customizable, but only because its pretty new.
this gun is amazing, I love it, and am VERY satisfied will its performence, the only thing is that if you use CO2 with it the reg. will get very cold while shooting, but if you buy a HP tank then it won't happen. I would reccomend this gun to any amatuer or pro player.
I would recomend this gun to anyone that loves paintball and wants a high quality gun that isn't to pricey. Now, STOP READING REVIEWS AND GO GET THIS GUN!!!!!!