Specialized Tapered Sacs of the corect full length for Skyline and other tapered pens have been missing from the marketplace for years.  Many people will use a #16 straight sac instead.  The resulting shortened sac thus holds far less ink and the writing capacity of the Skyline pen is rduced significantly.  Even the other tapered #16 sacs currently available are shorter than necessary.  They will fit the Demi size. for sure but leave a lot of sac missing to fill up an Executive or full size Skyline pen.  Our Taperd #16 Skyline Sac is long enouth to correctly fit an Oversized Executive Skyline and can be exactly shortened by the user to completely fill the pen barrel to its end.  The result can be as much as 500 extra words as compared to a too-shortened sac.  So if ink capacity is your thing, these sacs are for you.