The Aquash Water Brush by Pentel is a soft, synthetic brush with a large, flexible tip and a wide, hollow body. The perfect brush for using with ink (it works equally well with fountain pen ink and calligraphy ink), watercolours or gouache - you can fill the body with water (making it perfect for use with FineTec metallic inks) or simply dip the tip straight into your ink. Once you're finished, fill the body with fresh water and squeeze it through the brush tip for easy cleaning. The pen measures 15.5 cm in length and just under 2 cm at its widest point. Made in Japan.