Writing Feeling [UNI-, Gel Ink] Knock-type gel pen, the taste of the core is a replacement for the UNI-ball. It has a writing feeling that is superbly durable and light and robust with excellent gel ink. Because of the pigment ink, Nijimazu water, the drawings are almost faded, and the lines you draw are also vivid forever. Compatible Products: UNI-RT UMN-103, UNI-RT1 UMN-155-38, UNI-RT1 UMN-155 C-38 Product Name: Signo Co., Ltd Gel Ink Ballpoint Pen Core 0.38mm Black 10 Bottles UMR83.24