uni-ball Vision RT Retractable Bold Point Roller Ball Pens, 12 Purple Ink Pens (1741777) Exclusive ink system provides triple leak protection in pockets and airplanes and one paper Airplane Safe- ink will not explode or leak due to a change in cabin pressure during flights Spring loaded clip automatically retracts pen when is clipped onto your pocket Sealed, stainless steel tip prevents ink from bleeding out Set of 12 Bold Point Purple Ink Pens