REFILLABLE AND CLICK RETRACTABLE: The Tri-II pen-style click eraser easily clicks to expend the sturdy refillable eraser inside the barrel while also retracting when needed to preserve the eraser tip. COMFORTABLE, NON-SLIP GRIP: Each Tri-II eraser is designed with an ergonomic triangular, non-slip grip for a firm yet comfortable handle allowing for ease in erasing sessions.