Ceiling cassette cartridge neutral pen pen for plastic design, part of the handshake with soft elastic body and ensure the comfort of the writing for a long time. The use of internal refill is not blocked, the writing is very convenient, suitable for learning, office and other groups to use. Neutral pen is prevailing in the world at present a novel cultural activities, is a use of beads rolling writing medium of writing tools, writing between the medium viscosity between water and oily called neutral pen, therefore, neutral pen both fountain pen and a ball point pen of the advantages and