Features Material: Stainless steel and plastic. Note: Can be used for many European standard pens. Made of premium material, which is durable and practical. The interface can be easily removed for cleaning. Solve the problem that most pens are difficult to absorb ink. Lightweight and compact, easy to carry with you. The spring converter works with fountain pen takes 3.4mm converter. Packing list 1* Pen Ink Syringe Tools