This refill is usable...
, October 26, 2008
This refill is usable in UMN-207 Micro, UMN-152, UMN-105, or UMN-138. I tried it
in an UMN-138 pen body from Jet Pens and it writes smoothly. A friend
complimented on my writing while I was using it, and I pointed out it is not me
but the ink quality that is responsible.