Description One size 16 latex rubber sac for fountain pen restoration. One of the most common sac sizes. The size 16 latex sac is what you need for the restoration of Esterbrook J, SJ, and LJ pens, and many other pens. Please note: Price is per sac. Pen sacs are available in many different sizes and materials. Pen sacs are measured in 64ths of an inch diameter. Most sacs will need to be trimmed prior to use and are intentionally made longer than necessary. We offer Free Shipping on all orders over $59 for US customers, and for orders over $250 for our Canadian customers.