Our cat and dog tear stain care pen is carefully formulated with 1, 2-hexanediol and glycerin. Designed specifically to help clean and fade tear stains. The usage method is extremely convenient: Make sure there are no wounds in the pet's eyes and secure their heads. Rotate the pen so that the nozzle part at the top faces down to allow an appropriate amount of product to flow in. Gently apply to the tear stains around the eyes, avoiding the eyeball and covering the entire area. Let it absorb without rinsing. And it adopts a mild formula to avoid irritating the pet's eyes and the surrounding skin.