Uni-ball One 3 3-Colour Gel PenThe first three color gel pen from the Uni ball One series, this twist action pen combines black, red, and blue inks in one compact, easy to use pen. To change between colors, simply align the open wire clip with the color indicator on the ring. To replace the refills, hold the center band of the pen while rotating the pen body. Then, pull out the empty refill you want to replace with the new refill. It features the same rich gel ink the series is