These are colored gel pens from Sakura Japan. What I like the most about these pens are they are waterproof and highly luminous on black surfaces. Sakura Gellyrolls just glide over the surfaces so smoothly making it so fun to create doodles, mandalas, calligraphy. Be it any art form or just random doodling these are a good medium to express yourself at a very affordable price of Rs. 690 for set of 12 pens and are easily available on Amazon!