(1) This is exchangeable brush and is economical in comparison with other products. . (2) This is convenient to use because handle region is accessible to a molar tooth. (3) This is convenient to carry because you can keep brush at the end of handle. (4) It makes a hold in brush depository of handle and humidity disappears in depository. (5) There remain thin brush(blue color) and medium brush(light green color) and thick brush(white color) according to interval between teeth and you can choose the brush corresponding to yourself. (6) Refill cut the card according to dotted line and is available to carry.