Just noticed this on Kentech blog.
42259 Gear Diff 5mm O-ring (red, 8pcs.)
- Inner diameter is slightly smaller than the (black) P5 size you are using in the current Giyadefu, will give the effect of suppressing the leakage.
- To take tension by tightening strong minutes, O-rings, frequent replacement becomes necessary.
- O rings x 8 sets
link