This is Genuine Intrepid point Refill for Papermate Lubriglide, Aspire, PhD Pens, This refill is backed by crosspenmall quality assurance program..The refill is silky smooth. You have nothing to lose. Flawless and frictionless flow. Fits Paper Mate pen: PhD, Vintage 1971, Heart PowerPoint Slim; Vintage '98, Profile, #541 Profile, and double heart pen