Optima Fixed Tip 20, a unique tip used for cutting through gourds comes in two versions. The standard length pen (20) can cut through gourds up to 1/4" thick. The Long version (20L) is about 3/16" longer and can cut gourds up to 3/8"~1/2". It should be used on straight cuts (not curves) and should be used in a "sawing motion" for best results. It is ground much sharper than most blade pens so be careful not to cut yourself on this one!