Refills also fit Zebra Sarasa Stick and Sarasa Clip retractable pen bodies, if
you gently remove the small plastic thing at the end of the refill.
Unfortunately I've had two Signo Bit pen bodies crack where the body screws
together. I could not fix it with glue or tape, but the refill was brand-new
(and I luv the Bit!) so I tried to fit it in many different old pen bodies. I
did notice the ink dry&scratchy when I used a Sarasa Clip body because this type
of pen is meant to be protected by a cap when not in use, but the Clip is
retractable, no cap.