Zebra  Gel Pen, Retract, Non-Slip Grip, .7mm, CL Barrel/Black Ink (ZEB46410) Sarasa SE Gel Retractable Pens contain a smooth-flowing, water-based, pigment gel ink. Smooth gel ink delivers scratch-free writing. Ink is also acid-free and archival quality. Translucent barrel provides visible ink color and supply. Color of plunger indicates ink color. Refillable.