One late night I found myself scrolling on reflx lab's website and came across this filmstock I can find any information on.
Made in Heibei, China by Lucky Film Fresh date Film Format: 35mm black and white negative ISO: 50 (we recommend shooting at iso25) With this bulk roll, you can respool 19 rolls of 135 film (36EXP)
They only offer it in bulk rolls last I checked, and I have found a single thread on the rangefinder forums and one person experimenting with it a bit on threads, I believe. There's nothing I can really find on it, and honestly at some point in the near future I might just buy it to figure it out.