Schmidt Capless Rollerball

Both are capless rollerball refills, but they are different lengths. The shorter P8126 is around 100 mm long and appears in pens such as the Retro 51 Tornado, while the full-size 8126 requires a body designed for it.

The P8126 and 8126 use a 0.6 mm ceramic ball and produce a finer line than the related 0.7 mm 8127. The broad 8120 version uses a 1.0 mm tip.

Not automatically. Some pens designed around the P8126 can also accept Parker-style refills, but the P8126 is wider in places and will not fit every pen built for the Parker G2 format.

Its ink system is engineered to resist drying without a conventional cap sealing the tip. That lets pen makers combine liquid rollerball ink with twist or click mechanisms, provided the body is designed for the correct 8126-series refill.