Amazon カスタマー 2 The hop up unit was really badly setup and to begin with it is a really bad design, old. I had to fix it myself. The overall gun is cool and nice kick but the hop up unit is the worst ever. What year is bolt living. Upgrade your hop up units...Do not buy if you are afraid of fixing problems by yourself.The shipment was also poor and the gun's box came half open.The magazine is bad plastic, use some marui mp5 mags. they are more resistant, heavier and realistic and much better performance.It could be a 10/10 gun but they just messed up in some fundamental areas.Update: for further accuracy also check the barrel since it's meant to be hold by some screws. Those screws become fundamental since the bb may hit the outer barrel on the area of the muzzle due to being short. I've increased accuracy also by extending the barrel and became with the fixes like a sniper. Using my marui I think it was 205 mm inner barrel did the job.Summary: I recommend to change the inner barrel, the weapon can take a larger one and also fix the hopup unit by aligning it to center and better to glue it for avoiding inner barrel rotation since the hopup is very old design and does not fix the inner barrel well. Careful too because it needed some cleaning and the hopup unit is mostly hard to find a replacement so don't mess it up ;)