1. Appropriate Size for Application: this sketch rubbing sponge brush comes with 2 different sizes to meet your needs; The bigger pen measures about 0.47 inches/ 1.2 cm in tip diameter and about 5.94 inches/ 15.1 cm in total length, while the smaller pen is about 0.24 inches/ 0.6 cm in tip diameter and about 5.51 inches/ 14 cm in total length; For an artist or student, this variety in sizes means more room for creativity 2. Practical Double Headed Design: the blending sponge pen features a practical double headed design. The black tip of the bigger pen is applied for shadow side transition, for preliminary blending. The black tip of the smaller pen is utilized to handle the detailing. The white tip of the bigger pen is suitable for transitioning halftones to light and shadow sides or blending the light side, making your sketch more dynamic and visually appealing. You can use the white tip of the smaller pen on detailed sides 3. Ample Quantity: the package includes 24 pieces of blending stumps, in 2 sizes; This ample quantity makes it suitable for group activities in art classes and can also be a useful addition to your art kit, ensuring that you will always have pens on hand while working on your project. Due to the manual processing of natural wool, the white felt tip may contain some black wool, but does not affect the actual use 4. Reliable and Comfortable Material: the sketching wipe pen is made of quality sponge, felt and ABS. The black tip is made of sponge, and the white tip is crafted from felt, helping to blend different sides smoothly; The sturdy ABS shell ensures durability, comfortable grip, and long service life, providing a pleasant experience