Ngòi bút bi Blue Easy Flow 9000, gói 3 cây

I’ve been using these refills in my Retro 51 for a few weeks now and the ink just glides, zero skips even on cheap paper. The fit was perfect too, no wobble or fiddling to swap it in. Definitely the smoothest ballpoint refill I’ve tried.

The blue ink lays down so dark and wet that my handwriting finally looks decent, and it dries fast enough I don't smudge it on my notes. Swapped it into my Retro 51 in under a minute, and it's been gliding nonstop for a week now.

The ink flow is just effortless from the first stroke—no skipping or hard starts, which is exactly what I needed for a pen that sat unused for months. These refills slide into my Retro 51 with zero fuss, and the writing stays dark and crisp on every page.