The Pentel WOW! K437 is an OEM permanent gel pen, designed with a unique triangular-shaped barrel for easy handling and to prevent rolling off desks. It features permanent, smooth-flowing ink that is waterproof, fade-proof, and acid-free, ensuring a lasting impression. The stylish transparent barrel allows you to monitor ink supply, while the convenient clip makes it easy to attach to pockets or notebooks. With a latex-free grip for maximum comfort and control, this gel pen also includes a push top to advance the tip and a side button for retraction.