joa0102 's Japan Review

There are two types of barrels, 4mm and 3.5mm, and I was not sure which one to choose, but I chose 3.5mm because 4mm may not fit in the barrel or I may not be able to take it out even if it does.

One of them weighs 0.4g, which is not so heavy when you hold it by itself, but you can certainly feel the change when you put it in the barrel and try to fly it.
However, because it is an improved part that can be easily used, it is hard to set the setting and it is difficult to find the right one.

Also, if the barrel screw hole is shallow or the tip or shaft screw is long, the ball may interfere and not fit properly. (If the tip and shaft threads are cut a little, the ball will fit.)

If you are a convert when playing hardballs, it may be a good idea to keep a few conversion balls on the tip side to reduce the difference in setting between soft and hardballs.

The 0.4g weight makes the flight more stable.