Parker Jotter Limited Edition CT Ball Pen Perpetual Calendar Violet Notes & Ideas - Blue Ink Parker Jotter Ball Pen Perpetual Calendar - Body Color Violet Ink Color: Blue, Fine Point. Body Material: Plastic, Stainless Steel Mechanism: Push Mechanism Perpetual Calendar (How to use the calendar - Rotate the cylindrical rings and match the first date of every month with the corresponding day. For example, on 1st May 2013, match 1 with Wednesday)