Automatic pen with replaceable ink. Easy identification of ink color. Transparent body with a rubber grip. Tungsten carbide writing ball with a medium tip of 1 mm and a writing line width of 0.4 mm. The writing line length reaches up to 2400 m. The oil-based ink is durable, waterproof, and dries quickly (< 2 s). The easy glide ink formula ensures up to 35% smoother and lighter writing.