Use this to replace your old Chaco liner pen. All you have to do is unscrew the old and screw the new refill in place. This package contains one refill.Details:Available in multiple colorsMeasures 2.5" x 0.57" x 7.5"Made of talc and pigment powder with an ABS resin bodyRemove the stopper, keeping the opening uprightScrew in the new refill cartridge into the opening of the upper unitTilting the cartridge slowly to avoid spilling the powdered inkKeep the pen as vertical as possible during useIroning or dry cleaning may make the marks permanentMade in USA