I had actually bought a uniball one pen in Thailand and I loved the pen so so much but couldn't find the refill for it at all in India in local stationary which is when I started looking for refills for this pen online. Bumboo stationeries has outdone their efforts in making 0.38 mm refills possible. Because zento pen is my everyday use pen through which I write notes, my daily journal and track my habits on paper. A consistent pen is very important for me and I am grateful to Bamboo for making this possible!!! Already overstocked for this month! See you soon Bamboo❤️🌹